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I MAY, 1917
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2TRICAL. NEWS
ILLUSTRATED
LECTRIC TORPEDO DESTROYER
•SEE PAGE 10
LARGEST CIRCULATION OF ANY ELECTRICAL PUBLICATION
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THE ELECTRICAL EXPERIMENTER
May, 1917
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The Electrical Experimeeter
233 Fulton Street, New York. Publisht by Experimenter Publishing Company, Inc. (H. Gernsback, President; S. Gernsback, Treasurer;) 233 Fulton Street, New York
Vol. V Whole No. 49
CONTENTS FOR MAY, 1917
No. 1
ELECTRIC TORPEDO DESTROYER— Front Cover
From a painting by George Wall
A ONE-MAN ELECTRIC SUBMARINE By II. Winfield Secor
ELECTRIFYING THE AEROPLANE
THE AUTOGRAPH OF YOUR HEART By Samuel Cohen
COMBATING THE SUBMARINE By H. Gernsback
SOURCES OF ELECTRICITY
MAGNETISM PRODUCES REMARKABLE PHOTOGRAPHS..
By F. F. Mace
THE THERAPY OF LIGHT AND THE NEW "R-RAY"
By H. Rosenthal
"EDDY CURRENTS"— A Scientific Story By C. M. Adams
THE WASHINGTON'S BIRTHDAY RELAY PRIZE WINNERS
By W. II. Kirwan
ELECTRICITY AND LIFE— Second Paper
By Dr. Frederick Finch Strong
EXPERIMENTAL PHYSICS — Fourth Lesson
Bv John T. Furia, A.B., M.A., F.K.S. WIRELESS TELEGRAPHY— THE MARCONI HIGH POWER
Hi 12
IS
20
23
24
25
TRANS-OCEANIC STATIONS
By E. B. Pillsbury, Marconi Wireless Telegraph Co.
HOW THE AUDION REPEATER REPEATS
THE IONIC RADIO SYSTEM AND THEORY OF IONIC
TUNING By Otto E. Curtis, A.M., I.R.E.
RECEIVING MARCONI 300 K.W. SPARK STATIONS WITH
OSCILLATING AUDION
By Samuel Curtis, Jr., R.E., U.S. Navy
DISTRIBUTED CAPACITY AND ITS EFFECT
By Samuel Cohen
A STUDY OF THE LAW OF RESPONSE OF THE SILICON DETECTOR ; • • ; ■
CONSTRUCTOR DEPARTMENT— AN ELECTRICAL PARA- DOX OR SELECTIVE LAMP CONTROLLER
By Albert H. Beiler
AN ILLUMINATED STAGE SULKY.... By Harry S. Townsend A SIMPLE ELECTRIC MOTOR ATTACHMENT FOR PHONO- GRAPHS By R. U. Clark, 3d
EXPERIMENTAL CHEMISTRY— Twelfth Lesson ■■ ■•
By Albert W. Wilsdon
26 30
31
34
3K.
40
HE Radio Act of
states :
Every such license shall provide that the President of the United States in time of war or public peril may cause the closing of any station for radio communication and the removal therefrom of all radio apparatus, or may authorize the use or control of any such station or apparatus by any department of the Government, upon just compensation to the owner.
We now stand on the threshold of war; indeed, be- fore this issue is in the hands of our readers war will have been declared, or what is equivalent, this coun- try will be in a state of war.
Let us then be perfectly frank with each other, and let us face the situation as it behooves upright, pat- riotic, law-abiding citizens. The European war has taught us that messages sent from secret radio plants by spies have been of priceless value to the enemy. Small wonder then that hysteric officials of all the war- ring nations have exterminated every possible as well as impossible private wireless plant in their respect- ive countries. But to what good? True, every sta- tionary outfit has been dismantled or confiscated by the warring Governments, but as always : where there's a will there's a way. When the German spies in England and in France found that it was not very healthy to op- erate their outfits in attics or in house chimneys — for a sending outfit is soon located — they simply put their radios in touring cars, cleverly concealing the aerial wires inside of the car bodies. The apparatus too were easily concealed, and the English and French were outwitted simply because you cannot locate a moving radio outfit except by pure chance.
Which brings us face to face with the question : Did it pay the warring nations to kill the few private Radio stations they had before the war? We are honestly inclined to believe that far from being an ad- vantage, it proved an actual disadvantage. No one at all familiar with the technique of the radio art, doubts for one minute that if a spy has the courage as well as the funds — and spies always have both — he cannot be stopt from sending wireless messages if he elects to do so. Working under cover and by moving from one place to another, nothing will stop him.
If we recognize this truth it is to close all privately owned radio stations during the war. It will doLno earthly good and can do only actual harm. Now we do hot wish to appear selfish, nor do we wish to be classed as unpatriotic. Very much the contrary. If the administration, after care- fully considering all the facts, decides to close all privately owned radio stations in this country, we will not as much as raise a single word of protest. The administration knows what is best for the wel- fare of the country and in time of national peril we would be the last ones to annoy our officials.
But is it not true that our splendid body of over 300,000 patriotic American Radio Amateurs, scattered thickly all over the country, can be of inestimable value to the Government? Can not our red-blooded boys be trusted to assist our officials in running down spies, who probably would not be readily located otherwise? In our big cities thousands of ears lis- ten every minute of the day to what is going on in the vast ether-ocean. Trust our very capable American youths to ferret out the senders of questionable sig- nals or strangely worded messages. The very multi- tude of these amateurs is a priceless protection. Then again both our Army and Navy badly need Radio operators. What other country can furnish such a vast army of well trained and intelligent operators as ours, thanks to the amateurs?
When in 1916 the writer organized the Radio League of America, he incorporated in its statutes that every member should pledge in writing his station to the Government. Up to this moment the League has for- warded to Washington thousands of such pledges, among them every important amateur station in the country. These stations can be used by the admin- istration at a moment's notice. At least our amateurs are fully prepared.
Would it not be questionable wisdom to shut down all these stations that can and will do enormously more good than possible harm?
Let our officials ponder and let them consider fairly the facts in the case. That is all that we desire.
H. GERNSBACK.
THE ELECTRICAL EXPERIMENTER is publisht on the 15th of each month at 233 Fulton Street, New York. There are 12 numbers per year. Sub- scription price is $1.50 a year in U. S. and possessions. Canada and foreign countries, $2.00 a year. U. S. coin as well as U. S. stamps accepted (no foreign coins or stamps). Single copies, 15 cents each. A sample copv will be sent eratis on request. Checks ~nd money orders should be drawn to order of THE EXPERIMENTER PUB- LISHING CO., INC. If you change your address notify us promptly, in order that copies are not miscarried or lost. A green wrapper indicates expiration. No copies sent after expiration.
All communications and contributions to this journal should be addrest to: Editor, THE ELECTRICAL EXPERIMENTER, 233 Fulton Street, New
York Unaccepted contributions cannot be returned unless full return postage has been included. ALL accepted contributions are paid for on publication. A special rate is paid for novel experiments; good photographs accompanying them are highly desirable
THE ELECTRICAL EXPERIMENTER. Monthly. Entered as second- class matter at the New York Po«t Office, under Act of Congress of March 3, 1879. Title registered U. S. Patent Office. Copyright, 1917, by E. P. Co., Inc., New York. The contents of this magazine are copyrighted and must not be reproduced without giving full credit to the publication.
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3
4
THE ELECTRICAL EXPERIMENTER
May, 1917
GRAPHITE POTENTIOMETER
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THE ELECTRICAL EXPERIMENTER
H. GERM5BRCK editor H. W. 5ZZDR /J55DcmTE editor
Vol. V. Whole No. 49
MAY, 1917
Number 1
A One-Man Electric Submarine
WHILE Henry Ford has been urgently advocating the use of a one-man submarine of more or less efficacy, and compris- ing among other things a long collapsible pole extending from the minia- ture submarine, on the end of which there is supposed to be placed a torpedo or bomb which is to be exploded by the operator within the submersible, a number of other enterprising inventors have been engaged on
By H. WINFIELD SECOR
ception of one of these demons of war making its attack on the hull of a mighty Dreadnought, with a magnetic bomb prop- erly timed to explode a few minutes after its attachment, in order to give the opera- tor of the one-man submersible sufficient time in which to get far enough away from his victim to protect himself.
In the first place, it is the inventor's idea to make up these miniature submersibles of about the same size as the modern auto-
at two hundred horse-power for the above range, if the craft is to make a speed of 42 knots or approximately 50 miles per hour. In the event that the navigator of such a submersible should have to make a detour in order to get back to* the mother- ship or to his shore base, it would be ad- visable to equip the boat with an auxiliary gasoline engine as shown in the accom- panying illustration. 'Most probably un- der ordinary conditions, the operator of
The One-man Electric Submarine Here Shown in Detail and Also in Action Has Considerable Promise. It Can Dart Thru the Water at Torpedo Speed (50 miles per hour) When, Having Attached Its Magnetic "War-head" Containing the Gun-cotton and a Time Fuse to the Hull of an Enemy Vessel, It Can Easily and Quickly Make Its Escape at Mile-a-minute Speed. It Should Prove Ideal for Coast and
Harbor Defense.
a similar yet somewhat different problem. One of the most promising of these designs for a one-man submarine is that of Mr. ■Eric R. Lyon, the engineer who was respon- sible for the mastodonic two-hundred-foot high electric gyro-cruiser featured in our February, 1916, issue.
The accompanying illustration shows a detailed view of a one-man electro-me- chanical submersible along the lines laid down by Mr. Lyon, and also an artist's con-
Harbor Defense
mobile torpedo, or measuring say 25 feet long by 3 feet in diameter. This com- pares approximately with the dimensions of the latest type U. S. torpedo' with a range of ten thousand yards or 5.7 miles. When comprest air is utilized for propul- sion, the air being stored in the tank at two thousand pounds pressure to the square inch, the comprest air engine used in the modern torpedo (and which could be adap- ted to the one-man submersible) is rated
this new war engine would have no trouble in getting back to his base of operation by means of the comprest air equipment. It has been claimed by Mr. Ford and other in- vestigators that it is now possible to op- erate a gasoline engine under water by means of special absorption apparatus at- tached to the exhaust manifold of the gas- oline or other engine, and that this means of propulsion can be attached to submarine war vessels. If such is the case, then it
6
THE ELECTRICAL EXPERIMENTER
May, 191 7
"ELEVATING" CENTRAL.
The upper stories of the West Palm T.each Telephone Company's office in Flor- ida, which has just, had two floors added to it, was the scene of a remarkable en- gineering feat recently.
Under the new arrangement it became necessary to remove the big switchboard, at which the operators sit and make the connections that enable people to communi- cate with each other on an infinite var- iety of subjects, important or affectionate or merely frivolous, from the third to the fourth story. The move was made in the following simple but effective manner.
A platform composed of two pieces of 4x6 timber, on which was laid a floor of
2x12 planks, was built under the heavy switchboard — wide enough to accommodate the operators' chairs around the edge of the board. Slings were then placed about the whole business, to which a tackle and three heavy differential blocks, each cap- able of handling a weight of four tons, attached to a sling of log chains fastened
to a heavy beam at the top of the fifth story.
The switchboard, with the girls seated at it, and still carrying on their work, was hoisted thru a hole in the floor of the fourth story.
The work was carried on without a hitch, and the girls remained suspended until the floor had been rebuilt under the switch- board. There was not the slightest inter- ruption to business from first to last dur- ing the ascent. Nor did the subscribers, talking over the switchboard, suspect in their wildest utterings, that "Central" Switchboard Girls — chewing gum and all — were moving skyward, angel-like, all the while.
Right: — At Last! Central's Eleva- tion Completed. No interruption in Traffic and the Girls Are 10 Feet Nearer Heaven.
will mean that the one-man submarine will become all the more practicable.
Coming down to the means whereby this novel engine of war is to be used in car- rying out offensive operations, we see upon looking over the detail drawing that in front of the submarine there is a detachable war- head in the form of a steel cap which fits against the parabolic nose of the subma- rine very tightly. This war-head contains the usual quantity of gun-cotton or other high explosive. Suitable quick-acting mag- netic clutches enable the operator to in- stantly release the entire war-head ait any desired moment.
This submersible not only carries two dis- tinct forms of prime mover, but also car- ries the necessary gas tanks to supply a set of ultra-powerful oxy-acetylene flame nozzles, suitably disposed about the for- ward part of the vessel on the exterior, and by means of which the operator can burn his way thru any ordinary submarine net entanglement.
This feature is one of the latest scien- tific discoveries and involves the operation of an oxy-acetylene flame under water, which is made possible by blowing a stream of comprest air around the gas nozzle, and in this way forming a flame pocket in the •water so to speak.
Mr, Lyon is very enthusiastic on this par- ticular innovation, and has drawn plans for a one-man submarine which utilizes an ex- tra powerful and especially contrived set of these high power oxy-acetylene nozzles with which to burn a hole thru the bottom of a Dreadnought, causing it to founder soon- er or later.
Among the other interesting features of the idea here pictured we find a collapsible periscope which may be folded down into a suitable pocket provided in the top of the hull, and attached to which there is an air tube and also a (distress) rocket shute. When running submerged, a special air machine is used to supply the necessary- oxygen to the navigator. A powerful elec- tric searchlight is fitted to the front of the detachable war-head and by means of the small periscope shown the operator can see ahead at a considerable distance ufider the water. A compact but powerful battery is contained in the war-head which can sup- ply sufficient energy to energize the electro- magnets which hold the explosive chamber to the hull of the enemy war vessel once the operator has managed to approach close enough to accomplish this result.
The war-head also carries a special elec- tric time switch, which functions a few minutes after the war-head has been at- tached magnetically to the hull of the ene- my vessel, and which causes an electric spark to detonate the gun-cotton charge.
It has been argued by a number of naval experts that the One-man Submarine is doomed to failure for several different rea- sons. This, however, does not seem to be the case so far as we can see, and provid- ing the submersible is nroperly designed in its details.
Let us take a concrete case for example to show how the Lyon one-man ship de- stroyer would go about its task.
Assuming that these engines of destruc- tion, of which there would be most prob- ably several in each attack to make doubly
sure that the enemy would not escape, have been despatched either from a fort or oth- er point on the coast, or from a mother-ship several miles *-.stant from the enemy, the intrepid navigator of the 50-mile-an-hour submarine starts forth on his perilous jour- ney. With only his periscope exposed and at a distance of several miles, it is well known that a periscope projecting a foot or so above the water presents an almost im- possible target for ordinary gun-fire, and moreover, as the vessel darts forth on its way and as the range decreases between himself and the enemy, the buoyancy and submerging tank motor-pumps are manip- ulated so that only occasional sightings are made with the periscope. It thus be- comes very problematical whether the ene- my could hit the submarine. Also at a distance of say one mile, and in accordance with standard submarine maneuvering the submarine officer then proceeds to take ac- curate sightings of the enemy both with regard to the range and the direction geo- graphically, after which he submerges and may proceed at high speed at a depth of fifteen to twenty feet below the surface of the water (the same as modern torpedoes) and in a little over a minute or so, 'and providing he has gaged the enemy's posi- tion accurately, he will find himself in the vicinity of the bottom of the hull. Owing to the high speed possible with this minia- ture submarine, built like a torpedo, it should be possible for the navigator (in the event that he does not strike his mark, when he has gone the range calculated up- (Continaed on page 47)
May, 1917
THE ELECTRICAL EXPERIMENTER
Electrifying the Aeroplane
ELECTRICITY is being rapidly in- troduced in the new art of Aero- nautics as the illustrations herewith tend to testify. The greatest de- velopment in the art of flying is ■the aerial limousine or so-called Autoplanc illustrated in Fig. 1, which was exhibited .at the recent aeroplane show held in New York City. This aeroplane is built in the form of an automobile limou- sine and equipt with three •planes for the sustaining sur- face. Aside from its perfect -mechanical features its electri- cal equipment is exceedingly interesting, as the engine is automatically started by means ■of an electric motor installed •exactly the same as the mod-
the minimum air speed has been reached. It is mounted in any convenient position where the air flow is unobstructed.
The stallemometer is adjustable for any desired air speed, depending on the aero- plane on which it is installed. When the predetermined speed is reached, an electric contact is closed in the stallemometer, clos- ing the circuit thru an indicating lamp
I Fig. 3. Electrically \
I operated "Incidence
m Indicator" for show-
I ing best gliding and }
J| climbing angles. 1
Fig. 2. The electric "Stallemometer" warns the aviator, when his ma- chine is approaching a stalling condition by indi- cating that the minimum air speed has been reached.
at a dangerous angle. The white lamp sig- nals whenever the pilot dives at too steep an angle. The green light indicates the best climbing angle. Being of low voltage as well as low current consumption, the lights can be operated on a dry battery, encased in metal and installed wherever most con- venient. The signals are regulated by a vane operated by the air stream.
The lamp bank container is seen in the background. Each lamp is equipt with the proper colored screen and each con- nected to the required contacts enclosed in the incidence indi- cator chamber. The lead wires are led thru one of the support- ing tubes.
Aviators wishing to know at
Fig. 1. The latest in flying machines — the "Autoplane." It is an aerial limousine.
Fig. 4. Dead-beat "Clinometer" which shows angle of aero- plane with the earth.
Fig. 5. The "Sperry Automatic Pilot" which, by means of elec- tric driven gyroscopes, serves to control and maintain an aero- plane in any desired position: the pilot may drop bombs, etc.
-em automobile engine electric starter. The ■engine develops 100 horsepower and drives a four-bladed propeller place at the rear. The interior lighting is aecomplisht entire- ly by electric lamps and its ignition is of the very latest electrical design. Altho it -may seem that the machine was not made for speed, yet it has a speed range of sixty- five miles per hour and can si ;tain a weight of 710 pounds. It can carry two passen- gers and a pilot.
The stallemometer illustrated in Fig. 2 i's an electric instrument devised to warn the aviator when his machine is approach- ing a stalling condition by indicating that
mounted on the instrument board stationed in front of the pilot.
An incidence indicator increases the effi- ciency of an aeroplane by warning the avia- tor before he stalls and by enabling him to get the best climbing and gliding angles out of his machine.
The transmitter of the Incidence Indica- tor in Fig. 3, is mounted on a forward strut so as not to interfere with any part of the plane. The lamp bank or indicator is on the instrument cowl, always visible to the pilot observing other essential instruments. The red light warns the aviator before he stalls as well as when he begins climbing
any time the correct 'fore and 'aft posi- tion of the machine, with reference to the horizontal, can read it on the scale of the dead-beat clinometer illustrated at Fig. 4.
The operation of this instrument is sim- ple. Whenever the clinometer is tipt for- ward or backward by the motion of the plane, this movement is registered on a scale mounted on a wheel which is damped by floating in a liquid.
If the aeroplane tips forward, the scale moves upward, indicating in degrees below the zero line the exact angle. If the ma- chine tips backward, the scale moves down- ( Continued on pane 54)
8
THE ELECTRICAL EXPERIMENTER
May, 1917
The Autograph of Your Heart
By SAMUEL COHEN
ONE of the most important mech- anisms of the human body is the Heart. Its action in health and disease has been the subject of attention by numerous prominent physicians in all parts of the world, par-
Showing How the Extremely Sen- sitive Electrical Apparatus Is Connected up to Patient in Scien- tifically Determining Just How the Heart Beats and Why. The Apparatus Used for this Meas- urement Is Known as the "Elec- trocardiograph." (Fig. 2.)
ticularly those interested in fighting heart disease, the most unrelenting malady with which one can be stricken. Yet it has been said that 15,000 to 20,000 school chil- dren in New York alone are suffering from it.
In view of its most important function and delicate structure, cure, by way of operation, is usually im- possible. Therefore, the — — only thing left is to care- fully study the heart, lo- cate the trouble and de- termine the reasons for this trouble. A first aid in this direction is a bio- graphical history of the patient.
The rapid growth of this disease, and the rapid — — — - advancement of science ~ ^^^^™^^~ has led to the devel- opment of a new instrument called the Electrocardiograph. This instrument is really a modified Einthoven galvanomet- er, consisting of a very powerful mag- netic field produced by an electromag- net and excited by a constant direct cur- rent, such as the current given by a stor- age battery. A very short air gap is made between the poles of the magnet and in this powerful field a fine quartz filament or fiber is stretched. Delicate adjusting means are provided for controlling the tension of this wire. (See Fig. 1.)
A small diafram is placed on the center of this which closes two small holes that extend thru in each pole piece. These holes are the condensing microscopes and the projecting microscope to focus a fine beam of light to strike a moving photo- graphic film. If the wire is slightly dis- placed by the passage of an electric cur- rent thru it, it will naturally displace the small diafram and in turn permit the fine beam of light to pass thru the_ openings and strike the film placed opposite to the projecting lamp throwing out the fine beam of light. It will, therefore, be seen that by displacing the quartz wire in certain movements that a record will be made on the film accordingly. This quartz filament is connected to a Wheatstone bridge of proper dimensions and also to special terminals which are connected to the pa-
tient whose heart is to be examined. These terminals are three in number and are made of German silver plates, each of them being fitted with binding posts con- nected to the leads, connecting the plates with the sensitive galvanometer and Wheatstone bridge circuit. Two of the plates are se- cured to the arms of the patient, while the third terminal is strapt around the left ankle. Proper care is taken to see that the electrical connection between the body and the terminal is of low resist- ance and for this purpose a wet cloth which is sat- urated with a 20 per cent salt solution is placed be- tween the foot and plate and again the cloth is wrapt about the plate. The Wheatstone bridge circuit is balanced so that the resistance of the elec- trical path between ter- minals is constant, and this is obtained when the quartz string or filament of the galvanometer is in
a zero position.
It is evident that a slight addition of current to the galvanometer circuit will cause a displacement af the filament, which is recorded on the film. Since the contrac- tion of the heart creates an- electric cur- rent as found by various scientists, and as the intensity of this current depends
tN the present article we have one of the most interesting and startling revelations of what medical science, plus electricity, is doing to bring about a clearer understanding of our bodily actions. Herewith is pre- sented a true electrical record of a patient's heart, which shows the fluc- tuations occurring just before and at the critical moment when life ceased to exist. In other words, the patient died.
upon the intensity of the heart contrac- tion, it is therefore obvious that the fine quartz wire will be displaced a certain amount by the generation of current by the heart. With the contraction wave, the electric potential spreads over the heart and thus the galvanometer records the heart beat and also indicates the origin and path by which the current spreads.
An exact replica of the apparatus used in recording the pulsation of the heart is illustrated in Fig. 2. This shows the ap- paratus in actual use and also how the various electrodes are secured to the pa- tient. This photograph was taken at the time a record was actually being made of the condition of the patient's heart. The sensitive galvanometer is seen at the left, while the beam of light is derived from a powerful arc projector stationed at the ex- treme left, but not shown. The instrument at the extreme right is the photographic film apparatus. The film is driven at a definite and uniform speed ly an electric motor mounted at the bottom of the ma- chine. This instrument is placed in exact line with that of the telescope of the gal- vanometer pole-piece. The resistance box is shown on the shelf of the galvanometer table.
The instrument traces its indication of conditions in the heart by curves on the photographic film. These heart pictures
are as characteristic as finger prints or photographs. No '-'two individuals' hearts, beat alike, and the electrocardiograph, by its extremely delicate registration of the contraction of the muscle, readily shows the most minute difference.
A remarkable story of a dying heart is told by the accompanying curves registered by the electroca diograph. The graphs il- lustrating this remarkable story are shown in the third figure, and these were taken by Dr. R. H. Halsey, of New York City.
The records here reproduced form an almost complete electrocardiographic rec- ord of the heart b t during the last move- ments of the patient's life. Tho death was expected, yet its actual advent was much earlier than had been anticipated ; the transition from life to death was abrupt. The w ning of change is to be found in the lengthened conduction inter- val and in the changed ventricular com- plex of Fig. 5. That fibrillation of the ventricles was riot the immediate cause of death is clear from Fig. 6, taken when the usual signs of life were in abeyance ; the heart was profoundly affected, and the pa- tient past all possible hope of recovery before fi rillation ensued.
The record was obtained from a female patient thirty yea s of age, suffering from broncho-pneumonia of both lower lobes. The curves were taken one after the other in quick succession and are described in this order. In Fig. 1 the frequency of the heart is 75. The duration of the diastole* varies from 0.2 sec, to less than 0.1 sec, and is non-rhythmic. The up-stroke of P is quicker than the downstroke. The con- duction time is within the normal limits of 0.2 sec. T is upward in its direc- tion and of considerable excursion. In the second figure, the frequency of the heart is 80. There are the same vibrations in the duration of the diastole. The electrocardiograph Figures 3, 4 and 5 show — __ _ the different frequencies of rne heart at different periods. In curve 5, the frequency of contraction of the heart appears to have dropt to 45, while asso- ciation of auricle and ventricle is still pres- ent. The conduction time is 0.4 sec. ; double the time in the earlier record. Dur-
Close View ot the Einthoven String Gal- vanometer Used in Actually Measuring and Analyzing the Infinitesimal Electrical Cur- rents Produced by the Human Heart at Every Beat. Did You Know that Your Heart Was a Dynamo? (Fig. 1.)
ing the very brief interval between the taking of Figs. 5 and 6, convulsive gasps and a slow contraction of the skeletal mus- cles occurred. In Fig. 6, the change is re-
* Diastole is the period of rest between con- tractions of the heart.
May, 1917
THE ELECTRICAL EXPERIMENTER
(Above) — Figures 1 to 4.
markable, and the frequency of the ventricle has increased to 63 per minute. The remaining com- plexes vary in their detailed form, but are similar in general outline. In Fig. 7, there are no evidences of coordinate ventricular contrac- tion. The remaining records are similar; in Fig. 13, all movement ceased permanently, the patient having died.
When the heart takes a sudden jump to the fast rate, stops sud- denly and returns to the normal rate, a typical curve is made as in- dicated above. This condition is called a "flutter." The auricles of the heart sometimes contracting three hundred times a minute and the ventricles only one hundred and fifty times a minute !
By the use of the electrocardio- graph and a stethoscope connected with a microphone, the sounds made by the contractions of the heart are recorded with curves in- dicating the rhythm so that the exact point in the heart cycle of various normal and abnormal sounds may be recorded.
Electrocardiograph records showing the action of the heart under cer- tain treatment may be made and sent to physicians in various parts of the world, who by interpreting the curves can ob- tain information of great value in the treatment of their own patients.
In order to standardize such records, the tension of the galvanometer quartz wire is adjusted so that a current of one-thou- sandth of a volt will deflect the filament to such an extent that its shadow projected on the recording film will move one cen- timeter in both directions ! Since the wire is set to move a definite amount for a known voltage of current, the deflection shows the amount of current that caused it. The heart of the average individual causes a deflection which indicates the pas- sage of a current of approximately one to two one-thousandths of a volt. Thus it is known that it would require the heart beats of thousands of persons to generate enough current to light an incandescent lamp.
In conclusion it may be said that the conditions of the human heart can now be studied with far greater accuracy than was ever possible heretofore, thanks to the Electrocardiograph.
RADIUM AND CANCER.
"The Other Side of the Radium Cure" is the title of an article by Dr. J. H. Blaisdell, in the Boston H erald. This is of such great interest that we give it below, as many of our readers have undoubted- ly read the recent re- port of the Director of the Crocker Cancer Re- search Commission printed in these col- umns.
"Newspaper interpre- tation of medical sub- jects, vital to the inter- ests of the health of the community," says Dr. Blaisdell, "should be pe- culiarly conservative and well advised. To me your editorial com- ments on radium in can- cer on Wednesday
(Above) — Figures 5 to 9.
MAN SWALLOWED $20,400 WORTH OF RADIUM.
In an article treating on the use of "Radium in Surgery and Gynecol- ogy" in Radium, Dr. John M. Lee relates a peculiar accident which haopened in applying a valuable tube of radium. Sarcomata and epithel- iomata of the tonsils in several patients have yielded excellent re- sults. In one of mv 'first cases, a vigorous, powerful man, with more money than judg- ment, jerked his hea I backward thru the sup- porting hands of the nurse, and at the same time yanked the mucous- smeared and slippery braided silk thread out of my hand, just as I was about to seize the tubes in the pharynx
morning of this week seem especially open to criticism on this score.
"Briefly stated, your summing up of the findings of the Crocker cancer commission of Columbia University unqualifiedly placed radium in the discard as a 'cure,' damned it with faint praise as a palliative, and noted with the cheerful abandon of 'life opportunity given the medical profession to make 'the patient's condition worse than if he had been left alone.' Such- is the pessimistic side of the picture based on truth but, unfortunately for your readers, only half the truth. Simply because rad- ium cannot act as a 'cure' in inoperable or hopeless cases of systemic cancer is no reason why readers should be instructed to regard it as a discarded fad to the utter disregard of countless cases of early mal- ignant disease that this remedy has saved.
"Point out rather to your readers (re- ferring to the editor of the Boston Her- ald ) the significance of the recent pur- chase of many thousand dollars' worth of radium by the -luntington Hospital of Boston, as an example of how useful it is in experienced hands. Tell them of its curative effects beyond that of any other remedy in epitheliomas or cancers of the skin. Lay your emphasis on how radium can absolutely prevent cancers of the skin if people could be taught to have the early pre-cancerous possibilities such as keratoses, warts, moles, etc., removed before degeneration starts. By such statements it seems to me you would be doing the greater services to the com- munity and more rightly interpre- ting the findings of the Crocker Cancer Commission on Radium."
with forceps, and swallowed 175 milligrams of radium in three well-screened tubes. He refused immediate gastrotomy, and the tubes were past thru the alimen- tary canal at the average rate of nine inches per hour. No injury followed and he said : "None of the crowned heads of Europe have anything over me in luxuri- ous repasts, for I have had the only distinction of the consump- tion of a $20,400 meal."
(Below) — Figures 10 to 13.
TrR"
/V~~~\f
firm
The Above Electrocardiograph Records, Numbered 1 to 13 Con- secutively, Represent the Most Remarkable Scientific Analysis of Just What Does Happen In a Person's Heart Shortly Before and at the Exact Period When Life Ceases to Exist, or Death. By Inspecting These Charts of the Heart's Variations During the Last Moments of the (Female) Patient, a Victim of Broncho- Pneumonia One Can See How the Heart Started to Fluctuate Progressively, Finally Stopping Action at the Right End. (Fig. 13.) i
IO
THE ELECTRICAL EXPERIMENTER
May, 1917
Combating the Torpedo
WAR after all is but a game of chess. The greatest generals of modern civilization realized this so profoundly that every one of them had been at one time a good chess player. In war, as in chess, luck plays but an insignificant part. Given like equipment, the general who has the greatest strategical ability will win, whether it be in the field or on the chess- board. Also, if both opponents can suf- ficiently anticipate each other's moves, no one will — — — — win. In this case there will be a stalemate, as it has existed for over two years in France. But stalemates necessarily al- ways denote equal strength of both opponents and a stalemate often turns out to be a negative victory, for it is certainly not de- feat.
The present submarine —— — — — warfare is no exception to the rule of comparing war to chess, for the simple reason that it is an uneven game — all the powerful pieces are on the U-Boat's side and no Queen, Rooks and Knights on the other side of the board to defend the King. At least there was no defense worthy of the name up to a few months ago.
But science, as always, is progressing steadily and soon the submarine will have found its master, or at least its equal, with which to stalemate it.
Let me first correct a popular illusion. Almost every one of us thinks or speaks of the "deadly submarine," when, as a mat- ter of fact, the submarine itself is not only not deadly but a very weak contrivance at best. Point a 3-inch gun at it and it will vanish instantly. Send a 20-foot motor boat chaser against its periscope and the "deadly" submarine at once becomes deader than the pro- verbial doornail.
It is the subma- rine's deadly weapon — t h e torpedo — that has so far out-gener- aled the cleverest brains and has given the greatest statesmen untold sleepless nights. To fight the submarine itself is comparatively easy, given good guns and good gunners on board the attackt ship, providing of course that the enemy submarine command- er is foolish enough to expose his craft too much above the waves.
Several methods have been adopted of late to combat th? submarine, none of which have been great successes.
First, we have the smoke-screen — per- haps one of the most effective schemes de- veloped lately. By means of dense vol- umes of chemical smoke, blown around the ship by powerful exhaust pumps, the ship is enveloped almost completely in a fog- like screen and it becomes a very difficult target for a torpedo. The ship's bow, how-
This article appeared originally in the Sunday "New York American" of April 15t/i.
By H. GERNSBACK
ever, is nearly always exposed. The oth- er method is to protect the ship with strong torpedo netting suspended by means of booms from the ship. The torpedo upon striking the net is thus rendered harmless, as it never reaches the ship, unless the net- ting is made of rope and the torpedo is equipt with cutting blades. In that case the torpedo will strike the ship and blow it up.
But the one great drawback of the net-
OUR readers will find much food for thought in this interesting article. While the idea may not effectively stop enemy submarines from tor- pedoing every merchant vessel, we feel confident that we have shown a fairly practical way to obtain satisfactory results.
Mr. Gernsback is donating his invention to the Nation and he wishes it to be understood that he will not require to be paid royalties or any other considerations from Amercian ship owners. Foreign ship owners are not included in the above.
ting is that it is almost impossible to use it on a fast moving ship. It is too cumber- some and most important of all it greatly retards the speed of the ship, due to the excessive friction of the netting against the water.
The next — and poorest — means to com- bat the submarine is our widely advertised mounting-guns-on-a-ship scheme. Xo sub- marine commander in his right senses ex- poses more than one or two feet of his periscope when making a torpedo attack. And remember no torpedo attack is ever made at a closer range than 800 yards. Two thousand, and even four thousand, yards are very common nowadays. Im- agine a gunner on even a slightly rolling ship trying to hit an object one foot high
Patents Pending.
Top View of Ship with its Ten "Motor-Torpedoes" Which Operate Independently from the Steamer. An Approaching Enemy Torpedo Is Blown Up or Thrown Off Its Course by Explod- ing One or More of the Little Motor-Torpedoes at the Critical Moment. Note that the Modern Torpedo Leaves the Submarine in a Curved Line After Which Its Gyroscope Rights It on the Final Straight Run. (Fig. 1.)
and less than six inches in diameter, at a distance of 3,000 yards ! It simply can't be done. Scoring a hit under such cir- cumstances is pure chance, and don't for- get that the periscope itself does not stand still either. It, too, bobs up and down. In fact, at such a distance it is often almost invisible.
Mounting guns on merchant vessels nev-
ertheless is of distinct use, in so far as the guns will keep a submarine at a re- spectful distance and prevent the U-Boat commander from attacking the ship by means of his own gun-fire. But mounting guns on ships will never prevent a torpedo from finding its deadly mark. You can't shoot at a torpedo — the bullet is too small and the modern torpedo making 43 knots, i.e., 50 miles an hour, moves far too fast. After much thought on the subject, I came to the conclusion — that in the torpedo itself we have an effective weapon to combat the torpedo, strange as it may sound at first. You can combat a gun with another gun, and you can combat one rifle with an- other, as well as you can fight one aeroplane with another.
Why not combat the —— — — — — — torpedo with another tor-
™"^™*"" ™""^^~ pedo? It is all very pos- sible and simple if you know how ; as a matter of fact the idea struck me so favorably that I decided to apply for patents in all civilized countries.
Several navy experts have reported fav- orably on the idea, and while up to this writing no ships have been equipt with the device, I would not be at all surprised to see the idea put into practise very shortly.
Our front cover and the two accompa- nying drawings illustrate the idea clearly.
The underlying idea of the whole scheme is that it takes the torpedo an appreciable length of time between the instant of be- ing released from its submarine and the moment it strikes the attacked ship. Tak- ing the closest range at which a torpedo can be fired as 800 yards — and it cannot be fired much closer successfully — this gives a time of 55/100th or over half a minute to cover that distance, short as it is. Tak- ing the average range of 2,000 yards, it will take the torpedo l3A minutes before it will strike. These figures are for the latest type Bliss-Leavitt torpedo making 43 knots, i.e., 50 miles an hour.
But a torpedo, whether it runs on the surface of the water or submerged below it, always leaves a very noticeable "wake" in its course. Remember a torpedo is propelled solely by comprest air, c o m- prest up to 2,200 lbs. per square inch. This air must of necessity come to the surface of the water, as the torpedo runs over its course. The disturb- ance created thus gives rise to the al- most snow-white wake, which is very no- ticeable from a distance. Thus a man sta- tioned on a ship readily sees the wake as it comes nearer and nearer and he can gage pretty accurately just where the torpedo will hit. ' Escape for the compara- tively slow-moving ship is impossible, even if the engines were reversed instantly. The vessel's momentum would still be so great
May, 191 7
THE ELECTRICAL EXPERIMENTER
that the deadly torpedo would surely find its mark.
My proposed means of rendering enemy torpedoes ineffective is as follows : Fig. 1
sees to it that the speed of each torpedo keeps up exactly with the speed of the ship, for there should never be a drag on the cables. This is readily accomplished by
Detonafing snitches
Speed con trot ond reversing rheostat
Volt and ammeters Snitches
Cable reeling . drum A motor I
1
if* %
Dec/r,
Hoisting Davit
Flexible cable to itiip
Todynomo /
Electric Coble to other
mres torpedoes on*
right side of ship
Forward Most Torpedo Switchboard
Explosive Charge Motor- Torpedo
©
Propeller motor
Rudder control motor
Rudders Propeller
Concrete Ballasted tree/
means of rheostats, one for each torpedo. By cutting in more or less resistance the 12 H.P. motor can be made to run faster or slower and the torpedoes are thus easily controlled as to speed. By means of a double-pole, double-throw switch the little l/2 H.P. motor is revolved in either direc- tion, thus effectively steering the little craft so that it will always keep at a distance of some fifty feet from the mother ship. On the control board furthermore there is a switch connected to a storage battery from which wires are run thru the cable
PatentB Fending.
Fig. 2. The Electrically Propelled and Electrically Steered Gernsback "Motor- Torpedo." It Is from 15 to 20 Feet Long and Runs Independently from the Mother Ship. An Operator High Up on the Ship's Mast Blows Up the Motor-Torpedo by Electric Contact as Soon as the Enemy Torpedo Approaches Within 15 Feet. Both Torpedoes are Thus Destroyed.
shows the plan view of an average steamer, 600 feet long. On each side we observe five (or more) independent, electrically propelled torpedoes. Fig. 2 shows the construction of the torpedo itself. Briefly, it is built along the shape of the regulation torpedo and measures from 15 to 20 feet in length and from 3 to 5 feet in diameter. It has a 12 horse-power electric motor geared to the propellers and there is also a little J/2 H.P. motor geared to the rudder with which to steer the torpedo. Most of the space between the war- head and the motors is taken up with the usual charge of gun-cotton. This torpedo, un- like its other brethren, has a heavily weighted keel to pre- vent it from rolling over, for reasons which will be appar- ent later. On the back of the torpedo is mounted a steel mast-like structure thru which the control cable passes. This cable then rui.s to the deck of the ship over pulley arrange- ments as shown in Fig. 2. There is also a drum to take up the slack of the cable, or to play out more cable should the occasion aris~. The cable then runs up on the mast into a special turret located as high up as is feasible. Here we find one or more operators sitting in front of the electric control-board. All the cables from the star-board side tor- pedoes run into the forward mast-turret, while all the cables from the port side tor- pedoes run into the rear mast- turret. Thus each set of op- erators watches out for the safety of his side of the ship.
All of the torpedoes are painted in such a color that the operator can watch them readily and guide their indi- vidual course. Sitting at the control-board the operator
into the torpedo and thence into the de- tonator placed in the gun-cotton charge, Fig. 2. Throwing this switch will blow up our torpedo.
The war action of the idea is as follows : Our ship has left New York with all of the motor torpedoes hoisted out of the water and lashed se- curely to the decks. The mo- ment the need arises the tor- pedoes are lowered quickly into the water and the control operator starts the machinery of each torpedo, and in less than two minutes all of them should be running smoothly, fifty to seventy feet distant.
Suddenly the outlook scan- ning the waters with his bi- noculars sights the periscope of an enemy submarine and in less than a minute later our operator observes the rapidly lengthening wake of a death- carrying enemy torpedo. High up as he is located, he calculates that in less than two minutes the enemy torpedo will strike somewhere between his motor torpedoes Nos. 1 and 2 (see Fig. 1). By cut- ting in resistance into rheo- stat No. 1, he immediately slows up motor torpedo No. 1 thereby intercepting the path of the enemy torpedo. Or if, for certain reasons, he wishes to use his motor torpedo No. 2, he leaves No. 1 in its original course but by cutting out more resistance from rheostat No. 2, he speeds up the latter with the result that it advances faster than the ship and in this case as well it will intercept the course of the enemy torpedo.
Suppose he decides to use motor torpedo No. 1. He has nearly two minutes to jockey it for position and he will find little trouble to intercept the course of the hos- tile engine of death. His eyes glued to the enemy torpedo (or to its wake), his {Continued on page 68)
An Actual Photoqraoh of the "Wake" of a Modern Torpedo. Particular Torpedo Ran About 10 Feet Under Water, Having
Photo by Paul Thompson.
Attention Is Called to the Fact That This Been Fired by a Submerged Submarine.
12
THE ELECTRICAL EXPERIMENTER
May, 1917
Sources of Electricity
WtilLE most of us are familiar possibly with several sources of electrical energy, we do not always stop to think of the many possible sources which are little known, especially to the layman. We have endeavored in the present article, and with the aid of the accompanying full page illustration, to describe the principal known sources of electricity.
Static Electricity : This form of elec- tricity is that which we see when we stroke pussy's fur in a dark room and obtain a spark when the hand is withdrawn from contact with the fur ; or again, we may obtain the same form of electric shock or discharge by rubbing together two dissimi- lar substances, such as a stick of sealing wax with a silk handkerchief, after which it will be found that the electrified stick of sealing wax will attract bits of paper or small pith balls. A rapidly moving belt oitcn develops a considerable amount of static or frictional electricity, which will tend to discharge to earth whenever possible. One may often stand near such a belt, and by holding the knuckles or even the ends of the fingers near the belt, a heavy static discharge will take place between the belt and the fingers, the electric charge passing thru the body to earth.
One. of the usual and practical sources of such electricity is the static machine (Fig. 1) and when the handle of such a machine is turned, one or more insulating discs are rapidly rotated, and by succes- sive intensification of a very slight electric charge existing on the tin-foil sectors of these plates before the machine is started up, a surprisingly powerful static discharge is rapidly built up. This will manifest itself in the form of an electric spark, which crashes across the gap between two metal balls on the side of the machine. There are many other sources of static electricity but the whole phenomenon is practically the same.
Contact Electricity : It was Volta who showed that the contact of two dissimilar metals in the air produce opposite kinds of electrification, one becoming positively, and the other negatively electrified. There has been considerable discussion as to the exact action occuring in the production of elec- trical currents by the contact of two dis- similiar methods in air, and for a long time, says Silvanus P. Thompson, the ex- istence of this electrification by contact was denied, or rather it was declared to be due (when occurring in voltaic combinations) to chemical actions going on ; whereas, the real truth is that the electricity of contact and the chemical action are both due to transfers of electrons between the sub- stances under the peculiar actions of forces, about which very little is known with cer- tainty as yet.
Volta found that the difference of elec- tric potential between the different pairs of metals was not all equal, as while zinc and lead were respectively positive and neg- ative to a slight degree ; zinc and silver proved to be positive and negative to a much greater degree. The voltage ob- tained by the contact between zinc and carbon is 1.09 volts.
The phenomena of electrical currents produced by the contact of dissimilar methods is illustrated by Fig. 2. A dif- ference of potential or voltage is also pro- duced by the contact of two dissimilar liquids. It has been found that a liquid and a metal in contact exhibit a difference of potential or voltage, and if the metal tends to dissolve into the liquid chemical, there will be an electro-motive force acting from the metal toward the liquid. A hot
metal placed in contact with a cold piece of the same metal, also produces a differ- ence of potential, and lastly Sir Joseph J. Thomson has demonstrated that the sur- face of contact between two non-conduct- ing substances, such as sealing wax and glass, is the seat of a permanent difference of potential.
Galvanic Electricity : The primary bat- tery is generally denned as one in which electrical energy is produced by chemical means, without having to charge the battery from dynamo or other source originally. The simplest form of such a battery com- prises a glass or other vessel containing sulfuric acid and water, or any other oxi- dizing acid solution, and in which are im- mersed two clean metal strips, one of zinc and one of copper. Most of us are prob- ably familiar with the common form of primary battery used in American prac- tise for ringing bells and operating medi- cal coils in the form of the well-known dry cell, or with the zinc-copper-salam- moniac cell. In the zinc-copper-acid cell above mentioned, a continuous flow of electricity may take place thru a wire or apparatus which connects the two plates. When such a current passes, the zinc strip may be seen to waste away, or decompose by the electro-chemical action taking place, and its consumption, in fact, furnishes the energy required to drive the current thru the cell and the connecting wire or ap- paratus. In such a cell, the zinc strip forms the positive electrode or negative terminal, while the copper -strip forms the negative electrode or positive terminal. Such a cell gives about one volt potential.
Fig. 3 shows a unique form of primary battery known as the Hauck Circulation battery. In this battery, composed of sev- eral cells, the electrolyte or solution is caused to pass from a tank above the bat- tery cells, thence thru the first or higher cell, then thru the next lower container, etc This is a chromic acid battery with car- bon and zinc electrodes. The zincs are lo- cated in the rectangular porous cups while the two carbon plates are outside of the porous cups, all the space between porous cup and carbon plates, as well as between the carbon plates and glass vessel being filled out with small carbon pieces. In the porous cup there is a sulfuric acid electro- lyte, while the carbons stand in chromic acid. As the latter is caused to circu- late continuously from one battery to the next, all polarisation is done away with and we obtain a very steady and powerful current. The battery illustrated gives 6 volts and 60 amperes and can be used to charge storage batteries, run fans, or elec- tric lamps. It is one of the best chromic acid batteries ever designed.
Electricity from Gases : Fig. 4 shows the famous Grove Gas Battery invented in l£39. It shows how two gases are used to pro- duce an electric current. The two glass tubes contain platinum strips coated with spongy platinum. The glass bottle contains acidulated water in which the two glass tubes plunge, as seen. One of the tubes contains oxygen, the other hydrogen, as will be noted the gases make contact with the acidulated water. If we connect the two terminals with a galvanometer we will observe an electric current, the oxygen fur- nishing the positive, the hydrogen the nega- tive pole of the battery. Incidently we note that, as we consume current, the liquid rises in the two glass tubes, but twice as fast in the hydrogen tube as in the one containing the oxygen. As each tube is identical with the other, except for the gases, it follows that the current can be due only to the gases. Also different gases
produce different voltages and currents.
Pyro -Electricity or Electricity from Crys- tals : In the accompanying Fig. 5, we have several methods by which minute quantities of electricity are produced from crystals, when these are manipulated in a specific manner. Certain crystals, when they are heated or cooled, exhibit electrical charges at certain regions or poles, and such crys- tals which become electrified by heating or cooling are said to be pyro-electric. One of the principal crystals which manifest this peculiar action is tourmaline. The tourmaline has been cited in history, and is mentioned by Theophrastus and Pliny under the name of Lapis . Lyncurius . The tourmaline possesses the power of polariz- ing light, and is usually found in slightly irregular three-sided prisms which, when perfect, are pointed at both ends. It is in- teresting to note that in heating such a crystal as the tourmaline, it attracts light pith balls to its ends when electrified. If the temperature is kept steady, then no such electrical effects are observed either at high or low temperatures, and again the phenomenon ceases altogether if the crystal is warmed above 150° C. If a heated crystal of tourmaline is suspended by a silk fiber, it will be attracted and re- pelled by electrified bodies or by a second heated tourmaline. Among other crystals which belong in the pyro-electric family are silicate of zinc, boracite, cane sugar, quartz, tartrate of potash and sulfate of quinine.
Electricity is produced by the disruption and cleavage of certain substances, as for instance, when a sheet of mica is split apart, which action is usually accompanied by the production of a number of sparks, and both laminae are found to be elec- trified. If sulfur is fused in a glass dish and allowed to cool, it becomes powerfully electrified, which action may be tested by lifting out the crystalline mass with a glass rod. Chocolate is another substance which manifests such an electrification while becoming solidified.
Piezo-Elcctricity is the term given to that form of electrical energy produced when certain crystals are placed under pres- sure in a certain direction. With respect to the make-up of the crystal, it was found that if a crystal of calspar was prest be- tween the fingers so as to compress it along the blunt edges of the crystal, that it be- comes electrified, and retains its electrical charge for some days. This phenomenon is believed to be due in certain crystals to what is known technically as skew-sym- metry or hemihedry in their molecular structure.
Thermo-electricity: If we take two metal bars, one of bismuth and one of antimony, and join these together, it will be found that an electric current is pro- duced of an appreciable magnitude when the juncture between the metals is heated in the flame of a candle or other source of heat. To demonstrate that there is an electric current produced in all such cases, it is but necessary to connect a sensitive electric current-detecting device, such as a galvanometer to the free ends of the bis- muth-antimony couple, as it is called. If all parts of the circuit, including all sec- tions of the bismuth-antimony couple, are at one temperature, there will be no cur- rent produced, since the electro-motive forces are in perfect equilibrium. How- ever, when a junction between two such metals is heated, this equilibrium of the electrons and molecules no longer exists, and gives way to the production of an E.M.F. or difference of potential.
(Continued on page 71)
May, 1917
THE ELECTRICAL EXPERIMENTER
13
SOURCES OF ELECTRICITY
{For description see opposite page.)
14
THE ELECTRICAL EXPERIMENTER
May, 1917
Magnetism Produces Remarkable Photographs
WHAT causes iron, a dense, heavy substance, to ignore or overcome the laws of gravity and to dart thru space to a magnet? What is this mys- sterious, so called, attraction? Can this swift and sure motion of a heavy body thru space be caused by lines of force with- out motion, by lines of tension in ether or
BY F. F. MACE Superintendent of Public Schools, Pecos, Texas
sistent with the laws of nature, for all the facts of magnetism. Jk
But even this was not sufficient. The facts of nature had been distorted for years. These experiments, conclusive as they were, might be distorted and thrown aside. It must be proven beyond a shadow of doubt in some striking manner that there are actually currents about the mag-
of vibration, be such as to effect the pho- tographic plate? I could only try it, as I had tried other things, and hope to obtain the result sought.
The result justified the hope. Taking every precaution known to a photographer to prevent the result being effected by light or other influences I exposed a plate on which were placed a number of objects
Fig. 2. Photograph Taken in Usual Manner, Showing the Various Objects "Magneto- graphed."
by mere lines of direction, like lines of lati- tude or longitude? Can these lines of force tending or extending, moving with- out motion from one pole to the other, or lines of force or .tension "emerg- ing," without motion, from one pole and "entering," without motion, the other pole, produce the same result at both poles? Can any possible arrangement of the molecules of the magnet, supposing this arrangement to be brought about, possibly extend thru space and accomplish this result? Can any or all of these mir- acles, these things themselves contradic- tions of the known laws of nature, bring about another miracle — a result oppos- ing, apparently, one of the laws of na- ture? Is there a cause for these things in keeping with the known laws of na- ture?
These questions presented themselves when I first studied physics. They asked themselves more insistently when I began to teach physics, and they have been reiterated again and again in vary- ing form by every class of beginners whom I have appeared before. For more than fifteen years I sought to ob- tain an answer, a true answer, to these questions — an answer which would really account for the facts and which would be in accord with the other known laws of nature. For years only a faint glim- mering of the truth appeared. Then gradually the light grew stronger until I had worked out a clear and logical an- swer. But to answer these questions by pure logic based on the known facts of nature was not sufficient. Modern science demands experiment; tho New- ton and Galileo, and Leplace never per- formed an experiment but based their discoveries on the facts before them. Therefore, I worked patiently for years to demonstrate in a new way that which I knew to be true, until I had proven by experiment, that which I had proven by logical deduction, that the attraction of the magnet and all of the phenomena of magnetism are produced by the motion of ether currents about and thru the magnet, and until I was able to demon- strate the cause, nature, and direction these currents, and by the direction these currents to account logically, con-
Fig. 3. Here We See the Best "Magneto- graph" of the Objects in Fig. 2; It Was Made In a Vacuum.
net — that there is motion. How could this be done? I had worked with photography for years and was familiar with the X-ray. While pondering this situation the thought occurred to me : will the photographic plate — a photographic plate in a vacuum — prove this? A photographic plate is only affected by motion ; by light, which is ether motion; by chemical action, which is mole- cular motion ; by heat, which is molecular motion ; and by the X-ray, which is in
of
of
ig. 1. How the Author Arranged the Objects to e Photographed by a Magnet, Placing Them on Photo Plate Under the Bell of a Vacuum Pump, Permitting the Air to Be Exhausted.
motion. Even granting the ether currents about the magnet as I had proven them to exist, would their wave length, their rate
Fig. 4. Exposure of Photo Plate and Vari- ous Objects Placed Over a Magnet Under Atmospheric Pressure. Compare with Fig. 3.
under an exhausted receiver. At the end of three days I removed and developed the plate. Images were there, faint but un- mistakable. The experiment was a success ! I am sorry that I afterwards dropt and broke this first plate while attempting to handle it during a spell of illness.
With certain success before me I took every precaution to render the result be- yond question. In a dark room from which every ray of light was excluded, using only _ a perfectly safe ruby light, I placed ob- jects on a common photographic plate and placed them under the receiver of an air pump as shown in Fig. 1. These articles are shown in Fig. 2, as they appear when photographed with an or- dinary camera. "A" is a lead ring or washer. "B" and "C" are metric weights. "D" is a piece of gasket rub- ber. "E" is a broken metal buckle. "F" is a bone button. "G" is a scrap of acid-eaten zinc. "H" is a wooden button. "J" is a piece of sealing wax. "K" is a lump of resin. The magnet used 'is an ordinary steel U-magnet, weighing one kilogram (or 2.2 lbs.). The • msitive side of the plate is above and the objects lie on the sensitive side.
After the objects were placed on the plate under the receiver, twelve thick- nesses of black cloth were placed over the receiver and the air was exhausted. Then over all of this was placed a light- tight box and the .whole was finally wrapt in ten thicknesses of black cloth. The ruby light was then removed from the room and the room was locked and not reopened for twenty days. I may add that the whole operation took place after nightfall.
At the end of twenty days the room was entered after dark and the plate was taken from the receiver and de- veloped by ruby light as with an ordin- ary photograph. The result is shown in Fig. 3. The articles are lettered to correspond to Fig. 2. The one marked "D" was lost and is not included in Fig. 2.
Here is incontestable proof that there is motion, that there are currents, about a magnet. No mere line of force, no ten- sion in ether, no mere line of direction (Continued on page 70)
May, 1917
THE ELECTRICAL EXPERIMENTER
The Therapy of Light and the New "R-Ray"
By H. ROSENTHAL
THE therapeutic use of light has been known for ages ; in fact, it belongs to a period so remote that we are unable to determine even approximately the time of its introduction as a healing agent.
In the far East the earliest writings men- tion the use of light in the cure of disease, and in the comparatively more recent rec- ords of Central American aborigines we
Fig. 1. Appearance of Special Electric Arc Devised for Producing the "R-Ray" Radia- tions, Which Have Proven Extremely Satis- factory in Light Therapy Treatment for Certain Diseases and Ailments.
find accounts of miraculous cures per- formed by the Sun God. Even at the time of our early pioneers on this continent there are authentic reports of a custom practised by many Indian tribes, who treat- ed wounds and pulmonary afflictions, rheu- matism, neuralgia, et cetera, by exposing the naked skin to the mid-day sun, allowing the rays to fall directly on the part af- flicted. This custom was in vogue ages before the Spanish Conquest, and was com- mon among the aborigines of America, from Yucatan to the Arctic Sea.
We have, therefore, historic proof that light rays have been used from time imme- morial in the treatment of disease, and while modern science and modern meth- ods have attained the same ends, they have not changed the principles known to primi- tive man — but have merely developed the art.
As light rays are the oldest and most universally accepted 0 therapeutic agent, we 0 _ naturally ask — how are they translated into terms of therapy by the human body? To which the answer is, thru the medium of vibration and pene- trative force of quan- tity.
Light and electrical radiations are both waves that are pro- jected thru space at the same velocity. They are identical in nature, tho one wave length or radiation may differ from another, the same as one sound wave may vary in length from an- other, as found in the various tones or vibrations of music. Yet all wave lengths, whether light or sound, pro- duce their own corresponding vibrations and we therefore recognize all such vibra- tions in terms of light or sound.
Tn further proof of this existing vi- bratory theory we have color, which in reality exists only in the mind, for color
value is dependent solely upon the number of vibrations impinging upon the retina of the human eye. As for instance when the retina is stimulated by a vibratory force that approximates 400 trillions per second, the impression produced upon the brain is that of the color red; 750 trillion vibrations per second is interpreted by the brain as the color violet. And so on thru the scale of our visible spectrum. Yet, were the human retina sufficiently sensitive to receive and distinguish the many intermediate vibrations, it would perceive, thru the brain countless millions of tints and numerous values that lie between these two extremes.
When these countless mill- ions of tints are all combined we see only white. And tho we perceive and interpret white light as being white, still we know that it is not white, but the combined primary colors and their countless intermedi- ate tints. This fact is easily proved by simply passing a beam of white light thru a prism, which will show the primary colors making up the white beam.
Light vibration without penetration, force or quantity is in itself therapeutically neg- ligible. To have force, it should be direct, and to have penetration the source and quantity should furnish vibrations of prac- tically uninterrupted intensity.
One source of light which fulfills the above conditions is our own sunlight, which penetrates every portion of the human body and exerts a most powerful influence on its economy by oxygenating the blood, gen- erating hemoglobin and producing red cor- puscles. And when we Lecome Sun- Dodgers we cannot expect any other phy- sical condition than that which takes place in plants under like circumstances, and which entails on human beings the neces- sity of resorting to other means for making up the deficiency — generally drugs.
Summing up therefore the laws that gov- ern the therapy of light, we find it has the same relation to chemical actions which are governed by the chemic response set up in the substance or tissue, and not by the inherent quality of the ray; while all phy- sical conditions are secured in direct ratio to the penetrative power, quantity and vi-
in a given interval. So that from a ther- apeutic standpoint it is always highly im- portant to have at our command as great a number of these vibrations as possible; i.e., of the oscillatons. It has been averred by the medical profession that each and every corpuscle and cellular structure in the human body is composed of an infinite number of delicate receivers, each of which respond only when the right tune or vibra- tion strikes them. Thus when given ma-
S3
"0 I
^- K <0 <n <t M
tUCTWC
OSCILLATIONS
FROM
STORM IN SUN
-13
ELECTRIC OSCILLATIONS -
IN SMALL SPHERES
UK MAPT
Fig. 2. Chart Showing the Position Occupied by the New "R-Ray" in the Soectrum, Including the Relative Position of the X-Ray Vibrations and Ultra-Violet Rays.
4, 503, 599,627. 370,496 = Ultra violet photog. in vacuo
789.000,000,000.000 = Violet end of visible spectrum
.562,949,953.421,312 = Green light
451,000,000,000,000 = Red end of spectrum
281,474,976,710.656 = Infra-red
70,368.744,177,664 = Heat rays of solar spectrum
47,000,000,000 = Electric oscillations in small spheres
Oncein 4.7 seconds = Eiectiicoscillationstrom storm in sun
brating quality of the light employed.
All light waves possess two main charac- teristics that differentiate the effect pro- duced namely: first, the number of vibra- tions in a given interval of time, and sec- ond, the length of each oscillation or wave
Fig. 3. Spectrogram of the New "R-Ray," Showing Clearly Its Great Range in the Field of Light Therapy, Extending as It Does Beyond the Visible Spectrum.
jor, minor and chromatic scales to operate with, the skilled therapist can compel the brations of any cellular structure to re- spond to those which are produced arti- ficially ; and call into action complete ther- apeutic results, just as in music we call in- to play the various graduations of tone and produce perfect harmony.
The period of vibration or oscillations which make up light waves and which the human eye will respond to, are those above the infra-red rays or heat rays and those below the ultra-violet or invisible light rays. The difference between the two is that the vibration of the infra-red is very small and the wave length very long, while those of the ultra-violet region have a tremendous period of vibration and a very short wave length.
The therapeutical work that has been conducted points to the fact that the ultra- violet rays are most advantageous and con- sequently of greatest use in light therapy.
We know that light rays from such sources as the Finsen, Minin. Ultra-violet and X-ray are each capable of exciting a normal, subnormal or abnormal human re- ceiver.
However, our sci- entists not being sat- isfied with the belief of the existence of another source of vi- bration beyond the ultra-violet region, took another step in this direction which proved to be success- ful, inasmuch as they have found a region between the extrem- ity of the ultra-violet and the beginning of the X-rays. The re- gion is still unexplored, but there is little doubt that the greatest thera- peutic secrets lie hidden there.
It is believed that we are only be- ginning to learn of the real benefits to be gained by the scientific applica- tion of light rays by skilled therapists. The author, who has been engaged in this, as well as the electrical field of re- search for many years, discovered a new ray which he has christened the R- ray. The production of this new source of (Continued on page 47)
W<fVE T N'
LE icvns
METEI1S
dCTAVEi
1 6
THE ELECTRICAL EXPERIMENTER
May, 1917
Powerful Electro =Magnets Perform the Work of Many Men
The ordinary work of a man loading pig iron from the ground upon a railway car was from 12 to 13 tons per day. The
The Crucible Steel Company Have in Use at Their Pittsburgh Plant This Gigantic 62-inch Electro- magnet. It Can Lift 4'/2 Tons of Steel Bars and the Trip of a Switch Releases the Entire Load Instant- ly. This Class of Work Spells "Economy" in Big Letters and Foundries Everywhere Are Rapidly Awakening to the Fact.
lifting magnet, however, nas rendered it unnecessary for this laborious work to be performed by human effort, and the re- sults, as given in the unloading of the steamer, Erwin L. Fisher, at Indiana Har- bor, Ind., are given in brief below :
With a cargo of 4,000,000 pounds of pig iron, the time required to unload this ves- sel with twenty-eight men was two days and two nights, which corresponds to about 3,000 pounds per man per hour, or about 15 tons per day of ten hours. When the lifting magnet was introduced, the total time required for unloading was reduced to eleven hours and was done by two men, whose labor consisted in manipulating the controllers in the cages of the cranes. Thus two men and two magnets duplicated the work of twenty-eight men in less than one- fourth the time. Under these conditions the handling capacity of a man and a mag- net was nearly one thousand tons in eleven hours, or about 900 tons per day of 10 hours. This is fifty times as much as was accomplished by hand labor, or twenty times as much as is possible even under scientifically managed manual labor. Fur- thermore, the operation was chargeable with less than one-fourth the overhead charges, while the vessels were enabled to double their number of productive trips.
The lifting magnet has been adapted for the handling of materials in all branches of the iron and steel industry. It is used for handling pig iron, scrap, castings, bil- lets, tubes, rails, plates, crop ends ; for load- ing and unloading cars and vessels, and for handling skull-cracker balls and miscella- neous magnetic material. In fact it seems to be axiomatic that wherever magnetic material, and especially raw material, is to be handled in any considerable quantity, a lifting magnet can be used to advantage and will be a profitable investment.
The accompanying illustration shows in
a marked manner the practical application and efficiency of iarge electro-magnets used industrially. The first illustration shows a gigantic electro-magnet measuring 62 inches in diameter and swung from a crane at 'the plant of the Crucible Steel Company at Pitts- burgh. This mighty magnet has been photographed in the act of lift- ing 17 steel billets, each weighing 575 lbs., or a total of 8,925. It takes but a moment's reflection to readily conceive just how much man-power would be required to move this same weight of steel, not to men- tion the time occupied in moving it. A single operator, in this case the man operating the crane, lowers the magnet onto the steel bars and when in contact or nearly so, he closes the switch supplying the magnet with electric current. The magnet in- stantly becomes alive and exerts several tons of magnetic tractive power and holds the billets to its face securely, as pictured in the il- lustration. The crane may swing along for several hundred feet, car- rying its suspended load, and as soon as it reaches the desired loca- tion the magnet is lowered; when the operator opens the switch the magnet instantly releases its tons of steel.
The second illustration shows a powerful electro-magnet at work in the yards of the Chicago, Milwau- kee and St. Paul Railroad's West Milwaukee shop, the magnet meas- uring 43 inches in diameter and lift- ing in this case a locomotive drive wheel. The lifting magnet is an at- tractive proposition to-day and not only appeals in large sizes but in the very small sizes as well. The small hand type electro-magnet is particularly efficacious .for picking up quantities of iron nails, screws, etc., in hardware stores and stock rooms and finds application in a thousand and one different ways daily.
THE ELECTRIC HEATER FOR THE KITCHEN BOILER.
The accompanying semi-sectional view of an ordinary kitchen boiler shows how a recently perfected electric water heater is attached to it. This heater heats the water before you turn the faucet and not ■ — some time afterward. The tank is always charged with scalding water at any tem- perature you wish up to 2 00° F. (212 0 F. boiling point), or enough heat for about five baths — always on tap.
The heater has six steps — and the regulator is a six- point current con- trol. When no water is being drawn the heater will probably be cut entirely out so that no electricity is being used. Then as some water is drawn the. regulator picks out that step of the heater which will pump back into the boiler the same amount of heat that is drawn from the faucet in the hot water. At the sixth step the regulator ap- plies two full horsepower, stor- ing heat at 100% efficiency. It is claimed that this partic- ular electric water heater will operate on 15 to 20 per cent less energy than the cir- culation type heater, for the same monthly gallon production.
The present heater has been specially de- signed to make it self-cleaning. Under tne intermittent operation of the thermal control there appears a slight but constant opening and closing of the split heating tube, which readily cracks off all scale and any precipitate forming on the tube. This deposit accumulating at the base of the heater is then easily flushed out of the full size 1 '4-inch drain. This self-cleaning feature is, perhaps, next to efficiency in im- portance to the housewife to whom a burned-out heater means not only needless expense but several days' interruption in the hot water service and a recent engineer- ing report gives the external circulation type water heater four months in which to become absolutely choked with scale.
An Electric Heating Unit That Fits the Kitchen Boiler.
43-inch Magnet Lifting a Lecomotive Drive Wheel at the West Milwaukee Shop of the C. M. & St. Paul Railway. Another Instance of What the Lifting Magnet Is Capable of Doing.
CAN SINK SUBMARINES BY WIRELESS, SAYS INVENTOR.
Theodore Eichholz,. a young engineer and architect of Pittsburgh, has invented a wireless device that may be used to destroy submarines by causing an explosion of gases that are always present in submer- sibles, he claims. For several years the in- ventor was connected with the United States Corps of Engineers.
Mr. Eichholz stated that just recently a small experimental apparatus in his home on Neville Island sunk a small "dummy" submarine in the Ohio River, five miles away. The destroyed model was of steel and submerged to a depth of ten feet.
All submarines while under water are propelled by electric storage batteries which throw off a gas that pervades the hull. This gas, Eichholz says, he detonates by the wireless current and destruction follows. The apparatus will be submitted to the U.S. Government at once.
May, 1917
THE ELECTRICAL EXPERIMENTER
17
NOVEL TELEGRAPH INSTRU- MENT THAT RESPONDS TO VOICE.
Strange as the title may seem, yet the successful operation of such a device has been accomplished thru the researches of Mr. Christian Berger of New York City.
The accompanying photograph shows the complete equipment of the electric voice- operated telegraph instrument. The opera- tion of the device is not attained by the employment of a microphone of any kind, but by means of a sensitive sound-oper- ated circuit-breaker, which controls a spe- cial relay and which in turn operates elec- trically either a sounder or recording in- strument. The circuit-breaker is placed in a metal box which is seen in the center background of the photograph. This con- sists of a bent wire, properly balanced on an insulating block. The end of this wire presses lightly against the side of the box-, which makes a permanent contact when it is not disturbed. The second connection is made thru the metal box and this is ter- minated with one binding post of a bat- tery, while the bent wire is connected to one side of the relay electro-magnet, the op- posite side being linked to the other bind- ing post of the battery. The electro-mag- net actuates an armature which controls a cog-wheel by means of a projecting strip on the armature. On the same shaft with the cog-wheel is a drum upon which a number of contacts are secured. These are alternately connected, so that one will com- plete the electrical circuit when desired and when moved to the next stud, the cir- cuit will be opened. It is built on the lines of a step-by-step relay, which has been used some years ago for controlling mov- ing vessels by radio waves. The drum cir- cuit and the horizontal brushes which touch the drum studs, are connected in series with the recording instrument and battery.
The operation of the apparatus is ex- ceedingly simple as one must only be fa- miliar with the telegraph code, but not experienced in handling a telegraph key, as the transmitting is done by calling out the dot and dashes to the instrument. When a signal is made the sensitive sound actuated circuit-breaker opens the circuit which causes the armature of the relay to release it, thus giving a rotary motion to the cogwheel and in turn closing the re- cording instrument circuit. The complete equipment is very interesting when in ac- tion and possesses many diversified possi- bilities.
LOS ANGELES HAS WONDERFUL ELECTRIC FIRE TRUCK.
THE electric equipment of a new fire-fighting apparatus recently built by the Los Angeles fire de- partment has no equal in the country. This equipment is mounted on a ton and a half motor truck
As a precaution against any one accident- ally touching the foot throttle and speeding up the engine to too great a speed, when the wagon is standing at a fire, a special protective device has been provided, which consists of a hood which can be lowered and locked in a position, completely pro- tecting the foot throttle from the curious.
Los Angeles, Cal., Boasts of Having One of the Most Complete Electric Fire-fighting Trucks in the United States. The Equipment Comprises Five Powerful Searchlights Which Are Supplied with Power from Either a Large Storage Battery or the Dynamo Shown in the
Picture.
Speak to This Telegraphic Novelty and It Recor alent Dots and Dashes on a Paper T
ICELAND'S ELECTRICAL PAPER.
Elcktron is the name of an electrical magazine publisht monthly at Reykjavik, Iceland. The leading article is on the Ice- landic telegraphs and telephones, by Mr. Gisli J. Olafsen, who visited this country a year or more ago and studied American telegraph and telephone methods. This ar- ticle is printed in the Danish and English languages.
and was both designed and built by mem- bers of the fire department.
The equipment consists of five powerful searchlights, each rated at 250 watts, capa- ble of throwing a brilliant beam of liglit over 500 feet away. At this distance work at a fire can be carried on with great effi- ciency. Yet these lights are so arranged with diffusing lenses that it does not blind the firemen, even a few feet away.
The lights are 16 inches in diameter.
Three are permanent and two are portable, each be- ing attached to 320 feet of heavily insulated cable wound on a reel which can be unrolled, permitting the lights to be carried this distance into a burning building.
The handicap of a strange and smoky building is over- come by the use of these portable lights. They will penetrate smoke to almost an unbelievable distance, permitting the firemen to fight fires thru dense smoke with the greatest of ease. Power is received from eight large stor- age batteries placed behind the seat. These batteries themselves are capable of furnish- ing current for the lights for seven hours. Also installed on the right foot-board is a generator of 50 amperes, 25 volts, 1.25 K.W. This is run by a silent chain drive off the main propeller shaft and is con- trolled by a separate clutch, shown in front of the switchboard seen in the photo. The generator may be cut in or out at will, by means of this clutch.
ds the Equiv- ape.
A perfectly equipt switchboard is mount- ed on the right side immediately above the generator, having a marble back in an en- closed case with a glass front. It is equipt with a master switch for both the bat- teries and generators. Also an individual switch for each light and gages to show amperes and volts, a resistance cut-out and small lights to illuminate the board. Fuses of proper capacity are installed for each switch. To prevent damage to generator or batteries an under-load and an over-load switch is installed. This acts as a gover- nor, the purpose of which is to automatical- ly disengage the charging line from the generator when the rate of charge reaches a dangerous value or when the rate of charge is so low that there would be dan- ger of the batteries bleeding.
The portable lights are adapted to be used on a tripod. They are mounted on the wagon on a swivel connection with a one-inch diameter stem projecting, which fits into a socket fastened with a nut. A similar socket is provided on the tripod and when the light is set on the tripod, a large hand nut is provided which holds it securely. The light mounted on the tripod can be readily moved from place to place by one man. As he carries the light to he fire the reel automatically unwinds.
A wireless telegraph distance record of 11,500 miles was establisht by the steamer Sonoma, which pickt up messages from Eil- vese, Germany, when two days off Austra- lia, according to Royden Thomberg and Clio Bowers, operators on the Sonoma. Ellery Stone, assistant United States radio inspector at San Francisco, said it was the greatest distance achievement in wire- less telegraphy.
IS
THE ELECTRICAL EXPERIMENTER
May, 1917
MONSTER MOTOR GREATEST EVER BUILT.
We are told that at one time this old world of ours was inhabited by gigantic monsters. Well, we still have monsters — mechanical ones — that are far more pow- erful than any of which our ancestors
The Egyptians Built the Pyramids — but Se Builds an Electric Motor Developing the Com Horses. This Is the Largest Motor
knew. Take, for instance, the mastodonic Westinghouse reversing motor here shown, which was specially designed for driving 35-inch reversing blooming mills in large steel plants. When we realize that it has a capacity of 15,000 horsepower, the largest electric motor ever built, we need no fur- ther proof — we know it is monstrous. Some idea of its size may be gained when it is stated that the man standing alongside the mo- tor is six feet tall.
TRAVELING ELECTRIC SIGN FOR SHOW-WINDOWS.
The traveling electric sign here illustra- ted is a new moving feature sign for win- dow attraction that can be operated where heretofore the ordinary signs have been used. It displays the same amount of read- ing that ordinarily requires a 30-ft. length of space into a 3l/>-fo. space. The word- ing can be changed as often as desired.
Four 10-watt lamps are used for illuminating the sign, and the motor which operates the moving band uses only about 20 watts. Motor and lamps together use about the same amount of current as a 32-c.p. lamp. During the daytime, when the motor only is working, it uses less than one- half as much and the sign is equally effect- ive.
Any length of film from 6 ft. to 30 ft. can be used and changed in a few minutes.
This sign can be operated on either 100 to 120 volts direct current or 100 to 120 volts (60 cycle or less) alternating current by changing the connections at the termi- nal board.
The sign comes complete, ready for use,
e How Modern Man bined Power of 15,000 Ever Built.
The Travelin Cabinet, the
ELECTRIC LIGHTS CHEAPER THAN KEROSENE.
How much cheaper are gas mantles and electric bulbs than candles? The Society for Electrical De- velopment, anxious to en- courage a wider use of elec- tricity for lighting, has pre- pared figures showing that both are much cheaper than candles or kerosene, and that electric light, while it is more expensive than light from a gas mantle, is much cheaper than light from an open gas flame.
A recent test of six candles showed that for one cent only 2.68 candle-power hours were obtained. If electricity for lighting costs nine cents for a kilowatt-hour a 20-watt lamp can be lighted for 50 hours for nine cents. The efficiency of a 20-watt incandescent is a candle-power for 1.17 watts. Thus a 20-watt lamp will provide about 17 candle-power. It will burn 50 hours for nine cents or 850 candle-power hours will cost nine cents. One cent will buy 94.4 candle-power hours, or 35 times as much light as can be obtained from a candle for one cent.
Ordinary kerosene lamps with kerosene at 15 cents will give 72 candlepower hours for one cent. Figuring electricity at nine cents a kilowatt hour as above, we find 72 candle-power hours for one cent balanced against 94 for electricity, or a margin of 22 candle-power hours in favor of electrici- ty. With an open gas flame and gas cost- ing 85 cents a thousand cubic feet, one cent will buy 51 candle-power hours. For this price electricity will provide 94 candle-pow- er hours. Thus balancing gas against elec- tricity, we find the margin to be 43 in fa- vor of electricity. Gas mantles have be- come very popular and with best mantles one cent will buy 201 candle-power hours.
g Electric Sign Provides 30 Ft. of Word Space Moving Belt Presenting An Ever-changing Sign Adapted to Show Windows.
and can be operated from any convenient lamp socket. It can be set anywhere, or suspended with cords to hang at the top, middle or back of any show window.
MUNICIPAL TROLLEY OF SEAT- TLE LOSES MONEY.
The municipal street railways of Seattle, Wash., continue to lose money, as shown by the report of A. L. Valentine, superin- tendent of public utilities, in his report for October, the net loss being about $2,000 monthly. Since f.ie city light dept.rtment took over the street railway substations the power cost is being checked against the value of the substations, so that in October the street railways received $1,069 worth of power without cash outlay.
SAYS U.S. SHIPS HAVE GREATEST RADIO RANGE.
After he had inspected radio apparatus on a number of vessels recently, Secretary Redfield of the Department of Commerce said that American vessels have a wider range in sending and receiving messages than ships of other countries. He also as- serted that, from a comparison which he made of apparatus cn an. American and a British steamer, the wireless regulations past by Congress give greater power to ra- dio inspectors than do British regulations.
NEW VACUUM BULB RECTIFIER FOR BATTERY CHARGING.
The latest novelty in small rectifiers for charging storage batteries rated at 2 to 6 amperes charging rate and from 7.5 to 75 volts is here illustrated. It operates on a new principle for this class of apparatus. The discovery that made it possible is the perfection of the small bulb similar to that of an incandescent lamp, in which recti- fication of the current takes place. This bulb is filled with an inert gas and contains a tungsten filament and a grafite anode. It screws into a lamp socket in the outfit.
A black-japanned casing with perforated top furnishes the mounting and incloses all live parts. This casing carries the bulb, a fuse to protect against reversal and other overload and the compensator which re- duces the alternating current without waste- ful resistance and excites the tungsten fila- ment. For charging, the rectifiers need only be connected to a convenient lamp socket and the pair of leads attached to the proper posts on the battery.
The smallest unit is of 2 amp. maximum capacity. From a 115 volt, 60 cycle alter- nating current circuit it will charge three lead battery cells at 2 amp., six cells at about 1 amp., and eight cells at 0.75 amp. Between these figures the charging rate is proportionate. At 10 cents the kilowatt hour for current, the cost is about 1 cent the hour, including tube renewal costs. The weight is about 15 lbs. Medium size recti- fiers have a capacity of 6 amp., 7.5 to 15 volts, and are designed pri- marily for charging three or six-cell automobile starting or lighting batteries in home garages. This type is de- signed for 115 volts, 60-cy- cle current, but may be used on 105- to 125-volt circuits. The weight is about 15 lbs. The largest type is designed for use in public garages and service stations, and has a capacity of 6 amp., 7.5 to 75 volts. It will charge from one to ten three-cell storage batteries from a 11 5- volt, 60-cycle, alternating-current circuit. A compensator with fifteen taps is part of the device and a dial switch for in- stantly adjusting voltage ac- cording to the number of batteries to be charged. Amperage can be regulated be- tween limits of 1 and 6 amp. A single
in a 3/2 Ft. — Particularly
New Vacuum Bulb Rectifier with Control Handle and Ammeter, De- signed for Charging Storage Batteries.
three-cell battery may be charged by itself or any number up to and including thirty cells. The controlling devices, including ammeter, switch and regulating handle, are located on the front of the case as seen.
May, 1917
THE ELECTRICAL EXPERIMENTER
19
CIVIC FORUM MEDAL FOR DR. BELL.
Dr. Alexander Graham Bell, inventor of the telephone, before a gathering which filled Carnegie Hall, received the Civic Forum Medal of Honor for Distinguished Public Service on March twenty-first. This medal was presented in 1914 to Maj- or-general George VV. Goethals and in 1915 to Thomas Alva Edison. After many elo- quent speeches in his praise, Dr. Bell re- sponded modestly, endeavoring to share the tributes to him with those who have been associated with him in developing the tele- phone. <
"I may perhaps claim the credit of blaz- ing the trail," he said, "but I am embar- rassed at all the honor which has been done me, because so much of it should go to the many men who have since improved upon and extended its use — to such men as Mr. Carty and his associates. Why, I am not even able to understand some of the mechanism which they have introduced into the use of the telephone. When they telephoned from Arlington and were heard at Eiffel Tower in Paris, I could not see how it was done, nor could I understand how an operator in Hawaii was able to pick up the message."
Dr. Bell told how, shortly after he got the idea of the telephone in 1874, he had called on Professor Henry at the Smith- sonian Institution, who was then recog- nized as the greatest authority on electric- ity in America. Professor Henry listened kindly to his plan, and told him that he thought he had the germ of a great inven- tion.
"I told him that the trouble was that I did not have enough knowledge of elec- tricity," said Dr. Bell. "He said, 'Get it.' Now the fact is that, had I known much about electricity, I would never have in- vented the telephone. I would have thrown up the idea as wildly improbable. My study had been that of sound."
HEINRICH HERTZ. Born Feb. 22, 1857. Died Jan. 1, 1899. Inventor of Wireless.
HEINRICH HERTZ was born on Feb- ruary 22, 1857, in Hamburg, Germany. He received his early training in the engineering schools but at the age of twen- ty-one he decided upon an academic career
Heinrich Rudolph Hertz — Father of the Wire- less Telegraph. Upon His Scientific Re- searches and Practical Demonstration of Maxwell's Electromagnetic Theory, Marconi and Others Have Built Up the Commercial System We Know To-Day.
and entered the University of Berlin as a pupil of Von Helmholtz and Kirchoff.
Of the many gifted students of physics who have come forth from the celebrated
A NEW INSULATING MATERIAL.
"Galalith" is a bone-like substance similar in many respects to celluloid. It is manufactured from casein and formaldehyde. A solu- tion of casein is obtained by treating skimmed milk with caustic alkali, after which the solution is clari- fied and the casein then precipitated by means of acids and filtered. The water is then extracted under pressure and the product slowly dried over a period extending several weeks. The product ob- tained is casein plate, which is treated by thoro saturation with formalde- hyde and dried again. Galalith is said to be an excellent insulating mate- rial somewhat transparent, altho never completely so, and of a yellowish-white horn-like color. It is workable either in the hot or cold state, the cold gala- lith being softened by treatment in hot water. It is odorless, and much less inflammable than celluloid. It cannot be made into very thin sheets.
Senator Sheppard recently introduced an amendment to the naval appropriation bill calling for $50,000 to be expended in the erection of a radio station at Galveston.
TO ALL RADIO AMATEURS. rrfHE Department of Commerce of Washington, by its Secretary, the t / Hon. JVm. C. Red field, has kindly sent us the following information j of particular interest to all amateurs in the United States at the pres- J ent time. I
Secretary Redficld has issued orders that for the present no ne"w licenses to radio amateurs will be issued and the renewal of outstanding amateur licenses will be granted only by the Department upon special favorable re- ports by the radio inspectors. (This refers to sending outfits only.)
The Department also informs our readers, reminding them of the fact that the operation of transmitting radio instruments without licenses is pro- hibited under severe penalties, which, under the conditions of the time, would be exacted in the case of those who showed no- regard for the re- quirements of the law.
Up to the time that we go to press, the Department has not formulated final plans as to what steps will be taken in regard to radio amateurs as a whole, and -whether they will be allowed to continue to operate the same as before. It is our personal impression, however, that no drastic steps are likely to be taken by the Government as long as the amateurs cooper- ate with the Department. .
In view of this we most urgently and earnestly request all amateurs at the present time to refrain from using their transmitting stations except for regular work. In other words, all unnecessary gossip and fooling should be rigidly suspended for the present, particularly the "Q.R.M." nuisance which at best, only serves to irritate our officials, and makes their work harder. If amateurs do not voluntarily stop such annoyance the Government will certainly prohibit the use of all privately owned radio outfits.
These are no times to use the ether for a lot of nonsense; we all wish to help our country as much as we possibly can until normal conditions are restored again.
Always remember, that our Government has granted the radio amateurs more powers than any other country in the world, and in times of stress, it is up to the amateurs to show of what stuff they arc made by cooper- ating with our officials to the fullest extent of their powers.
THE EDITOR.
Berlin laboratory, there are probably none who have become so world-famous as Hein- rich Hertz. His qualities as an investigator were speedily recognized by Von Helm- holtz, who urged him while still a student, to undertake the solution of the prize prob-
lem proposed by the Berlin Academy of Sciences in 1879.
From 1880 to 1883 Dr. Hertz was an as- sistant in Von Helmholtz's laboratory; he then lectured for two years as instructor at Kiel. From 1885 to 1889, he was professor of physics in the Polytechnische of Karls- ruhe. In the latter year Clausius, a pro- fessor of this institution, died, and Hertz was selected as his successor in the Univer- sity of Bonn, where he spent the few re- maining years of his life.
Hertz's career as a scientific investigator covered a period of scarcely more than ten years, during which time he publisht thirty- six papers. Of these, a series of thirteen which appeared in Wiedemann's Annalen, were upon the subject with which his name will forever be connected, the laws of the propagation of electro-magnetic induction thru space. Of this great work, which af- forded a complete experimental verification of the Maxwellian theories concerning elec- tro-magnetism and the relation of electric- ity to light, there is no need to speak of its great importance to the scientific world.
The importance of Hertz's contributions to this great subject received instant recog- nition. It would indeed be difficult to find any other instance in which researches bear- ing upon a most subtle and difficult ques- tion, and absolutely devoid of basic elements of a utilitarian or even of a popular char- acter, having secured to their author such sudden fame. In addition to the recogni- tion of those wno were able to appreciate his work, Hertz received the acclamations of the entire world of thought. Fortun- ately, he possest a nature of such complete simple-mindedness that his sudden rise into a position akin to notoriety had no effect upon him. The unassuming bearing which had always characterized him remained with him to the end.
„,„„„■„-„„„..« In delightful harmony
I with the genuine and sim- 1 pie nature of the man were his surroundings in the quiet university town of Bonn. His laboratory was situated in the apart- ments formerly occupied as a dwelling by Clausius in a wing of the old pal- ace. Since electricity has become utilitarian, we find it associated everywhere with moving machinery and with the rush and bustle of modern indus- trial life, but in Hertz's laboratory, there was noth- ing to suggest the science of electro-technics. The place seemed to breathe that spirit of academic re- pose which to the inmates of the present day must have seemed to have van- ished altogether from the world. What might such a man, in such an en- vironment, have not been able to achieve, had he lived ?
The promulgation of the theories of Dr. Hein- rich Hertz in connection with Wireless waves, stimulated universal inter- est all over the world, which led to their use in the propagation of intelli- gence thru free space. In 1892, Hertz's re- searches upon the electric waves were gath- ered together in a volume under the title "Untersuchungen ueber die Ausbreitung der Elektrischen Kraft." Almost on the day of his death, another excellent translation of Hertz's researches appeared.
20
THE ELECTRICAL EXPERIMENTER
May, 1917
L
IEUTENANT Commander Par- ker, U.S. submarine 'F-609.' Our torpedoes useless. Proceed at once and see if you can do any- thing. Enemy's defense perfect. Admiral Gregg, U.S.N., Commanding Flotilla." T glanced up from reading this message, scrawled on a scrap of paper, to ask Park- er what it meant, but he was not there. I heard him in the forward compartment issuing orders in his rapid-fire manner.
It puzzled me, this brief dispatch which Parker had translated from the muddle of code words that had come in over my wireless. Could it be that the great fleet of submarines now in mid-Atlantic, sup- posed to be torpedoing the enemy's fleet
"Eddy Currents"
By C. M. ADAMS
we went out, thirty-two knots an hour, headed for the open sea.
As we went I picked up a message with my wireless which seemed to be related to the information in the code message Billy had received. It was a* press dispatch and read :
"There is a report that the defensive submarine flotilla which was to meet the imperial fleet in mid-ocean, is helpless be- cause of the excellent defense of the im- perial fleet against torpedo attack. The re- port says that the submarines have dis- charged every torpedo aboard and have not damaged a single enemy ship.
"The imperial fleet was reported by aero- scouts to be of sixteen battleships, to- gether with eight destroyers and followed
by our navy with its present equipment. How could we save our country from the invader? How could we stay off the de- feat which seemed iminent when that won- derfully trained army got into action against our meager forces?
I voiced these sentiments when, about nine o'clock I found Billy standing beside the conning tower on the open deck, look- ing forward over the double wave that marked our bows.
I felt free to ask Billy Parker much, for we had been old classmates at the Tech. school before he went into his electrical engineering work and I drifted off into mine, not seeing each other until I dropt into this craft as its wireless operator when the call came to me from the navy.
Once Again He Called to Start the Alternator. The Hum of the Machine Sounded and as Before the Switch Was Deprest.
and Found That It Was Held Down Six and a Half Minutes.
I Timed It Now
as it tried to approach our shores, had failed in its mission? Were the new powerful torpedoes, loaded with hundreds of pounds of high explosive, and the great mechani- cal fish which launched them, useless as far as defense was concerned? I wanted to ask Billy Parker these and many other questions but he was busy.
An hour after this message had .-ome buzzing in we cast off our moorings and were slipping out thru the harbor dotted with hurrying navy craft. We did not at- tract any unusual attention, for submarines were quite common sights in these times. Soon we past Sandy Hook, thru the line of patrolling cruisers, then out into the open sea. Our turbines were purring smoothly and our driving motors were spinning like great smooth-running tops as
by twenty transports carrying the invading army. There are also several enemy aero- planes which accompany the enemy fleet."
Evidently something was wrong with the defense planned by the navy officials. The fifty great under-sea craft were not doing their duty, which had been to sink as many of the invader's ships as possible. I puz- zled over this as I sat about waiting for my call and wondered what we would do now that our chief defense had gone.
What would happen when the army in those twenty transports landed on our shore, unprotected save by the scanty coast defense guns, made scantier by the appro- priation for submarines, and met our vol- unteer army in a pitched battle? This truly was a surprise, an overwhelming, unex- pected contingency which could not be met
Wireless operator was all I was good for, owing to my lame leg.
"What will happen now that our sub- marines are helpless?" I asked.
"It's up to the coast defense and the fleet if we can't stop them," he said, looking away ahead where the sea rolled under the faint stars.
Billy confided in me. His showing me the translated code message proved that. But this was a new turn.
"If we can't stop them?" I repeated blankly.
It had not occurred to me that we were going to try to stop them at all. I did not know why we were going, but it seemed obviously impossible for us to do anything in that direction when the rest of the sub- marines had failed.
May, 1917
THE ELECTRICAL EXPERIMENTER
21
"Yes, if we can't stop them," he repeated after me.
"Why, we won't be any better than the rest of them. That torpedo defense is too good," I argued.
"Who> said anything about torpedoes at all?" he demanded, wheeling and staring at me aggressively. ,
"Well, we're only a sub- marine," I retorted. —
"Does that mean that we necessarily have to use torpedoes?" he countered.
netic coil mounted on a revolving and in- clined carrier. This coil is shaped and wound so that its lines of force are kept within a very small area, in this case about one and three tenths square feet. Conse- quently when a metal object passes thru this relatively intense field, the induced current in the metal object will be sufficient
don't wei
I
"Why, asked.
"We haven't a thing that resembles a torpedo on this boat except the shells for that three-inch gun under the deck, and they will be about as ef- fective against a battleship as birdshot against an elephant."
I stared at him a long m^^^^^^^^ time then. He was seri- — ous as I could see, even in the starlight, but he was not lucid.
"Well, how are we going to get them then?" I asked, thinking that this natural question was expected of me.
"I'll show you," he answered, and stept down the ladder leading below.
I made to follow.
"No, stay there," he commanded.
I did, leaning against the steel conning i tower. A moment later I heard the sound of mechanism close to my head and glanc- ing up I saw something appear above the conning tower. I climbed upon the low rail and looked up to see what it was.
The steel plates had opened in the cen- ter and from the opening had emerged a hemispherical object, made of what ap- peared to be very heavy glass and measur- ing about three feet in diameter. Inside it was what looked to be a small mechani- cal device which seemed to run on a small circular track.
I was busy examining the device when I heard Parker beside me.
"That," he said, "Is the Feeler."
"The feeler?" I repeated, this was new to me.
"Yes, the feeler, a device that will locate any ship within ten thousand yards, with- out any part of our boat being seen."
I looked at the device again with in- creased interest. I could not see anything distinctive about it.
"Don't you see how it works?" Parker asked.
"No, I can't say that I do," I admitted.
"Come on down in the control room and I'll show you."
He led the way down the ladder and we went into the little box of a room under the conning tower where one is afraid to lean against the wall for fear of starting or stopping something necessary to the life of the boat.
He picked out a glass case from among the litter of instruments on the walls and pointed it out to me. It was not a very big case. In it were three dials, an elec- tric lamp and below it were three small control wheels. It looked very much like the other dials and wheels so thick about me, and was distinguished only by the word "Feeler" on the case.
"This device," he said, "works on the principle of electro-magnetic induction. You know what that is, the setting up of a current in something that cuts the field of force caused by a magnet. Well, up there in that glass case which will stand any pressure the boat hull will, is a mag-
"^^"E have publisht a great many stories in the past, but we do not hesitate to state that "Eddy Currents" is one of the very cleverest we have ever printed. Not only is it a rattling good story, but the scheme is so plausible that we venture to prophesy that it will be actually tried in the not too distant future. And then, the submarine will earn its adjective "deadly" in the fullest sense of the term.
to make a difference in the load on the coil. You see that don't you?"
I did. That was perfectly plain sailing, electrically.
"Well then, when this load comes on, the lamp lights up as a signal, and this dial here which is really a calibrated gal- vanometer, shows how far away the ob- ject is."
He pointed to one of the three dials which 1 had noticed was calibrated in yards.
IN THE JUNE "E. E."
An interview with Thomas Alva Edison, including some new photo- graphs of the famous inventor.
Electricity and Life by Dr. Fred- erick Finch Strong. Part III of this interesting and valuable series.
Woman's place in the Wireless game — A page of female radio operators who have made good.
The How and Why of Radio Ap- paratus. Part IV. Spark Gaps.
The Calculation and Measure- ment of Inductance. Part III of this valuable series by H. Winficld Secor and Samuel Cohen.
Another gripping electrical tale — "In the Way" by C. M. Adams. Don't miss it!
Feature Article — "Electricity's Aid to the Fair Sex" — of interest to everyone.
Building a High Frequency Alter- nator for use in Radio by S. Cohen.
Experimental Physics. Fifth Paper by John J. Furia, A.B., M.A.
An Electric Player for Tuba- phones.
A home-made electric searchlight for the amateur by Frank M. Jack- ■ son.
"What are the other dials for?" I asked.
"They are to give the angle of the coil, both in the horizontal and vertical planes. You see both are calibrated that way. These wheels here turn the coils about and raise and lower them, and this third wheel operates the mechanism which raises
the coils clear of the conning tower."
I saw then the whole perfect simplicity and accuracy of the device. I marveled at it.
"Then you can run under water with- out even a periscope exposed and locate the exact position of the enemy," I said.
"Exactly, you understand it perfectly,' he replied.
— — — — — — - "Then you can aim your
~~"^™"™""~"— torpedo with accuracy," I went on.
"Torpedo !" he snorted with an exasperated frown. "Didn't I tell you that we didn't have one of those antiquated devices aboard this craft?"
"But," I went on, "you must have something to sink the enemy after lo- cating him."
"We have," he said, his face brightening hope-
_ — fully-
"Well, what is it?" I asked, puzzled.
"Look here, Dick Hartman," he said in mock seriousness, "do you mean to tell me that after seeing this feeler work, you can't understand how we could sink a ship? You, a graduate of the best technical school in the country and a practical electrical engineer, can't understand that?"
I contest that I did not.
"Then you're either asleep or haven't the least trace of imagination," he said, turn- ing away in disgust.
"Well, how do you do it anyhow?" I asked.
"I'm not going to tell you. I'll let you find out for yourself first," he retorted with a show of his old boyish perversity, and walked into his room and left me wondering in front of the feeler dial.
But I could not follow his line of reas- oning to its end. I thought of it as I tried to sleep that night, while the motors thrust us forward and our long hull swayed gently as we topt the crests and fell into the hollows. I puzzled over it as I sat at my instruments and waited for my call, or anything else my receivers could pick from the ethereal vibrations about us. But I could make nothing of it. I could see no way, no means by which wc could sink an enemy ship with this curious little feeler device which with all, was exactingly ac- curate.
All that night we ran and all the next day. I did not ask Billy any more about our boat. Pride perhaps kept me from doing this, and impatience at my own lack of perspicuity and imagination. And then too I was busy with my own work and other things that came up, which had to be done in the crowded under-sea craft.
I prowled about it in what spare time I had, trying to see what I could between tricks at my table. I found that it was quite the usual large-sized submarine, of which the navy had an even hundred not counting ours. It was driven by electric motors supplied by turbine driven genera- tors forward. It was provided with the usual gas absorption system which made it possible to run under water with our steam power, without discharging any ex- haust gases; this, the 'first important in- vention of the Naval Consulting Board. But I found the forward torpedo room locked and none on board had gone into it since they had been on board, none save the chief engineer, Dickenson, a man from Parker's own electrical company, which had built this curious boat and sent it out (Continued on page 66)
LIBRARY
11 <? patent nrri/c
22
THE ELECTRICAL EXPERIMENTER
May, 1917
118 VOLTS CAN KILL.
The Ontario Electrical Inspection De- partment of the Hydro Commission are out hot foot after delinquents who try to work in jobs without permits and convictions are being rendered every week, says a writer in the Electrical Safety Magazine.
Never Touch Electric Light Fittings or Wir- ing While Standing In a Bath-Tub or On Damp Floor, as the Consequences May Prove Fatal.
One person is to come up before the board for refusing inspector admission to premises and others for not returning to remedy defects on jobs before expira- tion of inspectors' notices.
In the City of Toronto, in the month of October, a young man, nineteen years of age, was in the bath-tub and, so far as his parents knew, he was enjoying the harmless and healthful pastime im- mensely, judging by the sounds of splashing and rubbing emanating from the keyhole.
The happy sounds were suddenly in- terrupted by a deathly shriek, and his parents upon breaking into the room, found him doubled up with the coils of a long portable lamp cord wound round him and the portable lamp in the bath. The lamp was an ordinary brass desk lamp provided with the silk cord.
The cord was worn, showing bare copper spots. What he was doing with a lamp in the bath no one knows.
The bathroom was provided with a brass bracket well up above the bath with a portable socket.
Test revealed that 118 volts, 25 cycle cur- rent was used, one side grounded, the fix- ture itself clear of ground and well insu- lated from both the grounded and un- grounded sides of the circuits.
The investigations show that he was killed by coming in contact with brazed cord carrying 118 volts, 25 cycle current.
This proves two things: First, that 118 volts can kill, and secondly, that indif- ference to bare spots on cord is dangerous.
One quarter of a dollar spent on renew- ing this cord would have saved a young life, a doctor's bill, an undertaker's bill, and the parents' grief. Is it not worth while? Safety First! should be the slo- gan of every user of electric service, whether for half a dozen lamps or for a large factory. Again — when you stand on a damp or wet floor or in a bath-tub, don't touch an electric switch or fixture!
their entire life a pair of these shoes, the manufacturer states, will provide the wear- er protection against circuits at pressures up to 20,000 volts and will not cause the discomforts of many of the rubber soles.
The shoes are molded by a process simi- lar to that used in making automobile tires. The shoes contain no cement and have no seams, but are vulcanized into a solid piece under high pressure on aluminum molds. No hand work is employed in the process. This method of manufacture makes it im- possible for the completed shoe to peel or come apart and prevents injury from oil, gasoline or grease.
In order that the shoes may, in the inter- est of safety, be distinctive, they are all made exactly alike with brown heels, white soles, brown vamps and black tops. The white soles are made of a rubber composi- tion like that employed in certain types of coal miners' shoes, which have been found to give eighteen months of constant wear. When this white sole wears thru, a layer of red rubber, which will itself with- stand a pressure of 20,000 volts, is exposed The appearance of the red rubber is a sig- nal or reminder to the wearer that, altho his shoes still will withstand 20,000 volts, a new half sole should be immediately ce- mented or vulcanized in place.
The brown rubber also extends under the white sole. It is this piece of material which is capable of withstanding high po- tentials. One of these shoes, when tested
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insu/afed so/e of red rubber tested eo.ooo v\
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Remarkable New Shoe for Lineman Which Is Capable of Withstanding 20,000 Volts. Note That No Nails Are Used.
in the laboratories of the Edison Electric Illuminating Company of Boston, under the direction of the accident prevention com- mittee of the National Electric Light Asso- ciation, showed the following characteris- tics :
"Side of shoe, dry, punctured at 31,500 volts, and again at 34,000 volts ; sole of shoe between electrodes in oil punctured at 55,000 volts; 20,000 volts applied from salt water to salt water for one minute and 30,000 volts applied from salt water to salt water for forty-five seconds did not punc- ture the rubber."
point, were about seven feet above the lo- comotive, and current is sent thru them at a pressure of 11,000 volts, 25 cycles.
Directly over the engine, which was giv- ing off a medium black smoke, the air seemed to flicker at the rate an electric light would if connected to a 25 cycle cir- cuit. This *vas only noticeable when the quality of the smoke's carbon element was just right. That this flickering was not due to heat waves I proved by the fact that objects when looked at thru heat waves seem to bend or wave from side to side and move upward, while objects seen thru this vibrating air did neither, and when the quantity of carbon decreased as the wind blew, the flickering effect disappeared.
The cause of this phenomena I attribute to the attraction and repulsion of the car- bon particles in the smoke and as the cur- rent reversed they were drawn upward and downward for a very short distance, while being dissipated into the atmosphere. The effect was not noticed a few inches above the wire. The weather on January tenth was slightly hazy, with no sun at 3.30 p.m., when this effect was noticed. In bright sunlight it could not have been seen. If my explanation is in error I shall be pleased to hear the views of some of your technic- ally inclined readers.
MAKE YOUR PHOTO PRINTS BY ELECTRICITY.
The electric photograph printer illustra- ted has been brought out for both pro- fessional and amateur use. A feature of the device is an automatic switch which is operated only when full pres- sure is placed on the pad. The pressure pad is placed in position by a hand lever which controls the automatic switch, the 'light being turned on only when full pressure is exerted on the pad. The light is -turned off before pressure on the pad is released, thus avoiding any blur- ring in the prints and assuring absolute, contact. A locking device is provi- ded which relieves the operator of the necessity of maintaining pressure on the lever during the exposing period. With a slight grip on the release catch, the lever can be freed. A locking de- vice is also provided, permitting the white light to be turned on and the pres- sure pad elevated to permit accurate ad- justment of masks or vignettes. In the light box of the smaller printer are one ruby and four clear incandescent lamps, and in the larger one there are one ruby and six clear incandescent lamps. The printers are designed to take 100-watt gas- filled lamps.
ELECTRICITY LIGHTS NEW PIPE.
An electrically ignited pipe which lights the tobacco at the bottom of the bowl in- stead of at the top, thus avoiding the col- lection of moisture in the stem, is the new- est in smokers' inventions.
A LINEMAN'S SHOE THAT WITH- STANDS 20,000 VOLTS.
A leading American maker of lineman's protective devices, which for several years has been marketing protective shields to cover wires and cross-arms where men are working, has now developed an insulat- ing shoe for electrical workers. Thruout
PECULIAR ELECTRICAL PHENOMENA. By Walter J. Howell.
While standing about one hundred feet away from the tracks of the New York, New Haven and Hartford Railway January 10, 1917, a large steam engine pulling a heavy freight train past at the rate of five to eight miles per hour. The railroad is electrified by overhead wires, which, at this
Electrically Illuminated Photograph Printer Equipt with Automatic Switch Actuated By Printing Frame.
The printer is being made in two sizes — 8 in., by 10 in., and 11 in., by 14 in.
May, 1917
THE ELECTRICAL EXPERIMENTER
™° RADIO LEAGUE
^AMERICA
H. Gcrnsback, Manager
H ON OR ART MEMBERS CAPT. WHG. BUILARD. U. S.N. NIKOLA TESL A PROF. REGINALD FESSENDEN. DR. LEE DE FOREST.
W. H. Kirwan, Master of Radio Relays
The Washington's Birthday Relay Prize Winners
WELL, boys, you did it ; the first official Trans-continental M.S.G. (message) No. 1 from the Mayor of New York to the Mayor of Los Angeles, went thru with the customary speed and
Mr. Edward B. Duval!, Who with Mr. A. P. Smith, Operating Station "3AK," Baltimore, Md., Won "First Prize" in the Washington's Birthday Relay.
reliability of all the Relay messages we have worked on. The special stations sent the westbound message from New 'York on this night from 2 ZK at New Rochelle, using 8 YI, 9 XM and 9 ZF to 6 EA, which last station is in Los Angeles, Cal. Considering the time, one and one-half hours, and the great "QRM" (interference) and the repeating of message on account of misspelt words, it was truly wonderful.
The westbound message used special stations only and was as follows :
To the Mayors of Los Ange- les, Cal., and Seattle, Wash.: On behalf of New York City, I send cordial greetings to Los Angeles and Seattle, and best wishes for the success of the Radio System. (Signed)
John Purroy Mitchel, Mayor of New York. Thousands of amateurs cop- ied this message with varying degrees of exactness thruout the country, as four heaping bushels of letters have shown. This was the first relay attempted
By W. H. KIRWAN, (9XE) Master Radio Relays, Radio League of America
by the writer, the necessary notices of which were publisht in this magazine. Some of you did not hear about the Re- lay because you are not regular subscrib- ers. Let this be a lesson — Get your name down so that you will receive your maga- zine promptly and regularly.
Now, here comes the sad part. You will see "by the papers," that on this night we had good radio weather as far as the Rockies, but the writer had studied the weather man and looked for trouble south- west and west, and we had it ! A healthy young cyclone was dancing merrily over Texas, Arizona, New Mexico and Califor- nia, and the tail end of a regular old-time "QRM" storm was making life miserable for the boys in the war west, but with it all, 6 EA got the message direct from 9 ZF. 6 DM, who volunteered to help 6 EA, put on full power and promptly blew the fields of his gap motor, leaving 6 EA to do the honors and, by golly, he did.
Seefred Bros., delivered this message to the Mayor of Los Angeles, and promptly received his reply, but QRM and QRN were so bad by this time that it was a physical impossibility to get it thru to 9 ZF. 6 EA stuck to his post, however, and got the message thru the next night, too late for 9 ZF to find anyone out of bed. 9 XE arranged for all eastbound amateurs to be on the job, and the message came thru fine, being delivered to the Mayor of New York by Mr. Geo. C. Cannon, 2 ZK, the next morning early.
Lots of you kept me company by stay- ing up all night waiting for the return message and now you know why it could not get back on schedule. The return mes- sage was as follows : To the Mayor of New York City:
On behalf of the City of Los Angeles,
sage. (Signed) Fred I. Woodman, Mayor of Los Angeles.
By counting up the total time consumed on each message, we -call the race between Specials and Amateurs a tie, with the
Radio Station "3 AK," Baltimore, Md., at Which the Wash Birthday M.S.G. Was Successfully Received in Record
I return your greetings and wish you continued prosperity. Congratulations to Amateur Radio on the successful mes-
Mr. A. P. Smith, Joint Operator of Radio Station "3AK," and to Whom Full Share of the Credit for the Receipt of the Relay M.S.G. Is Due.
handicap of the low wave length of the amateurs, giving them a slight preference for a decision in their favor, but my form- er contention still holds — that the amateurs are not yet pre- pared to handle these trans- continental messages with as great a degree of certainty as the Specials, unless they can get together and have emergency stations in the long jumps.
I am not posing as an expert, but candidly believe that fifty miles, worked absolutely sure, with a great number of relay stations, is more reliable than a few with long jumps, working only when the conditions per- mit. This is what we propose to do now by organizing the "Q.R.M. League." In it, there will be a chance for all of you to help and not just a few thru- out the country who want to work every night, and who want you to shut up. You know, boys, this good old U.S.A. is a pretty big place and these Relays are run for your benefit, but there are some few in this country who (Continued on page 61)
ington's Time.
24
THE ELECTRICAL EXPERIMENTER
May, 1917
Electricity and Life
IN the March number of The Elec- trical Experimenter the author point- ed out that high-frequency currents, when properly tuned, acted as "Vital Boosters," increasing all the functions of the body and helping it to resist and
The Construction of High-Frequency Apparatus for Medical and Lecture Use By FREDERICK FINCH STRONG, M. D. Lecturer on Electro-therapeutics, Tufts Medical School, Boston
(Second Article)
The author has interviewed a number of the more prominent authorities on med- ical electricity and they agree as to the vitalizing effects resulting from daily high frequency treatment.
Anyone who possesses a V\ or l/z K.W. wireless transformer, operating on 110 volt, 60 cycle A.C., can easily construct an effi- cient high-frequency outfit for medical or lecture use. The complete equipment in- cludes a .01 microfarad glass plate con- denser, Tesla coil, inductance, spark gap and electrodes.
The Tesla coil is made as follows: (Fig. 3) On a paper mailing tube 2j4" diam. and 14" long wind 480 turns of No. 34 D.C.C. copper magnet wire. Set up the tube in the lathe, apply a coat of orange shellac, spin on the wire, apply a second coat of shellac and allow to dry thoroly. The winding occupies twelve inches, leaving a margin of one inch on each end of the tube. Leads of light auto (ignition) cable are ^soldered to the ends of the winding. A '.strip of waxed, corrugated paper M, 5" wide is wrapt around the center of the sec- ondary tube and on this is wound the pri- mary, consisting of four turns of heavy high tension auto cable, and thoroly se- cured by tape; at least a foot of cable should project from each end of the wind- ing to form the primary leads. Place the coil in a wax tight box made without nails and embed it in a mixture of four parts rosin and one part beeswax. It is safer to boil the coil for an hour in the insulating mixture before placing it in the box. Coils made in this way by the writer are still giving good service after fifteen years of use.
The greatest source of trouble in a medi- cal high-frequency outfit is the spark gap; the one described below is the outcome of many years experiment. If properly
made it will run daily for months without deterioration. The spark takes place be- tween two pieces of brass rod 1%." diam. and 3^4" l°ng, turned and tapt as shown. The sparking surfaces are turned in an- nular grooves with a 60 degree tool. If
Fig. 1. View of the Strong Conical Oudin High Frequency Coil Delivering a Veritable Tree of Sparks Several Feet in Length.
Fig. 2. Another View of the Strong High Frequency Coil Producing a Perfect Sheet of Flaming Sparks to a Grounded Conductor. The Exciting Energy Is but 1 Kilowatt.
throw off disease. This vitalizing effect is not due to the mere liberation of heat in the tissues, for it is produced by the very high-voltage ( "Tesla") currents as well as by the heavy amperage ("D'Arsonval") cur- rents from which the thermic effects are usually obtained.
When the writer demonstrated the first therapeutic Tesla Coil and the first Vacuum Electrode — (in 1896 before a Boston Medi- cal Society) — and suggested that this meth- od was destined to come into general use as a vitalizing agent, he was laughed at by his colleagues ; yet to-day there is scarcely a well equipt physician's office in this coun- try or in Europe that does not contain some form of therapeutic high-frequency appa- ratus. Even the barber-shops of the pres- ent time have their small "Violet Ray" out- fits ; and these are not by any means "fakes" for they produce real results, such as the relief of headache, neuralgia, skin diseases, et cetera.
Unlike other forms of electricity, these currents may be administered to patients with perfect safety. In twenty years' ex- perience in electro-therapeutics the author has never known of harmful results from the use of Tesla Currents applied thru a vacuum electrode. The heavy amperage ("D'Arsonval") currents, owing to their deep thermic effects, should be used only under the direction of a physician. The writer is a firm believer in the use of Tesla currents in the home — if each mem- ber of the family could receive ten-minute daily treatments from a small high-fre- quency apparatus, the general standard of health would be greatly increased. This has been demonstrated in hundreds of cases.
Conical Oud/n Co/l
f/g.6
Details Are Given in This Article for Con- structing a Reliable and Powerful Oudin op Tesla High Frequency Coll, Suitable for Phy- sicians' Use. This Type of Coil is the Most Efficient Ever Designed.
your lathe has an automatic cross-feed you may set it to twenty turns to the inch, and turn a spiral groove instead of the annular rings. After finishing, the brass pieces are heavily silver plated and mounted in the usual manner as shown. (Fig. 4.) For currents over J4 K.W., a plate of silver should be soldered to the brass before turn- ing the grooves. This gap will also give greater efficiency in wireless work as com- pared with the usual stationary gap.
The connections for the various parts of the apparatus are shown in Fig. 5. An important feature is the use pf an external inductance or tuning coil "d" in series with the Tesla coil. It consists of 32 turns of No. 8 bare copper wire, wound on a frame 8" diam., with J4" between turns. Edge- wise wound flat copper strip is better- but more expensive. (d Fig. 8.) This coil when used in series with the Tesla primary enables us to tune the oscillating system in perfect resonance when the capacity of the patient's body is added to the Tesla terminal. Effects are produced which are impossible with any other method. The beautiful High-frequency Effluve or brush- discharge, so valuable in treating pulmonary diseases, and which so few modern high- frequency machines can produce, is obtain- able by the use of this series inductance. It may also be used, by short-circuiting the Tesla primary, as an auto-transformer from which may be derived heavy "D'Arsonval" and "Diathermic" currents as described in the next article of this series.
For stage demonstration and public lec- ture work the writer employs a large high- frequency resonator which produces a tree- (Continued on page 59)
May, 1917
THE ELECTRICAL EXPERIMENTER
25
Experimental Physics
Instructor
LESSON FOUR GASES AND THE ATMOSPHERE (Concluded)
AIR expands when heated and be- comes lighter in weight. If we have a confined bodv of air such as in a room, for example, and there is a source of heat in the room, the air near the source will expand
Simple Apparatus Comprising Box, Candle and Two Lamp Chimneys for Demonstrating the Principle of Ventilation.
and become lighter and the heavier air at the top of the room will fall, forcing the lighter air upward. Thus it is that the air near the ceiling is always warmer than that near the floor. This shows the ne- cessity of opening a window at both the top and the bottom for best ventilation. EXPERIMENT 19—
Fig. 15 shows very simple apparatus which can be made with practically any material available, for demonstrating the behavior of air near a source of heat. C, is a box thru which holes have been cut to admit tubes (or glass lamp chim- neys) B. A is a lighted candle. The arrows show the direction of the current of air.
EXPERIMENT 20—
An interesting experiment giving sur- prising results and having a simple ex- planation can be performed by the use of a spool and a visiting card. (If no visit- ing card is available, the ace from a poker deck which you may have "up your sleeve," will do very well.) Place the card up against the bottom of the spool as in Fig. 16-A and the mouth against t e top of the spool. Blow vigorously and then let go of the card. One would naturally expect that blowing against the card would blow
Closed/ end
Closed; • end
Open end Y
Fig. /<?
A Glass Tube, Sealed at One End and Filled with Mercury, Will Support a 30-inch Column of Mercury, Owing to Atmospheric Pres- sure Acting Against a Vacuum. The Prin- ciple of the Barometer.
it away whereas actually the card stays fast, close to the bottom of the spool. Sometimes, when the conditions are not
By JOHN J. FURIA, A. B., M. A.
in Physics and Science Master, Riverdale Country
just right; the card slides off perpendicular to the direction in which one blows, but to avoid this a pin should be stuck thru the card's center and then into the hole in the spool (care being taken not to stick it into the wood of the spool). Fig. 16-B shows diagrammatically what happens. The air from the mouth passes down the hole in the spool and out along the upper sur- face of the card. It is a well-known fact that the pressure is greatest where the speed is least and vice versa. The air underneath the card is practically still, while that just above the card is in rapid motion, and hence the pressure against the card from beneath is greater than that from above. Hence the card tends to get as close to the spool as possible and does not fall.
EXPERIMENT 21—
In the First Lesson we learned that at any depth in a liquid there is a pressure due to the weight of the liquid above that depth. We also learned that air has weight and consequently we conclude that the air (at the surface of the earth) has pressure due to the weight of the air above it. The higher up we go, the less air there is above us and hence the pressure is less. If one sucks in at the stem of a pipe (see Fig. 17) at the bowl of which is stretched a piece of sheet elastic, the pressure of the air above it pushes the elastic down. Suction is not a mysterious force ; it is simply a removal of the air from one side so that the pressure from
/"^ fosifiol) of elastic
• ■/ fop sheet wlii/e sucA/i/g
L / out the air
^ ill F>9- 17
Removing the Air Within a Pipe Bowl by Sucking In Thru Stem Allows the Pressure of the Air to Push Elastic Diafram Inward.
the other side can act without being op- posed. Actually, when the air is entirely removed from the pipe, the pressure above the elastic sheet is fifteen pounds on .each square inch; i.e., the weight of the col- umn of air from the earth's surface 1 the end of the atmosphere on each square inch of the earth's surface is fifteen pounds. A column of water thirty-three feet high and one inch square weighs fifteen pounds and a column of mercury thirty inches high and the same area, weighs the same (mercury weighs 13.6 times as much as water) .
EXPERIMENT 22—
Seal one end of a narrow tube having a diameter of about one-quarter inch and about fifty inches long. Fill the tube with mercury and invert it carefully and place the open end in a cup containing some mercury. The mercury in the tube will fall until the height of the mercury in the tube is about thirty inches above the level of the mercury in the cup. The same level is kept no matter how long and how wide the tube is. The air pressure on the cup's surface acts against the mercury in the cup and it is transmitted thru the mer- cury to the open end of the tube. Since the tube was filled with mercury and there was no air at the sealed end, we get the same effect as if air was there originally
School
and was sucked out; i.e., there is no air pressure in the tube and the air pressure outside can hold up the mercury to a level of about thirty inches. If now the seal is broken the air rushes in and the mer- cury in the tube falls into the cup. (See Fig. 18-A.) The pressure of the atmos- phere changes from place to place and from time to time. It is, therefore, im-
|
Fig. 16 |
|
|
* Card / |
|
|
Spool* Yr^, |
|
|
. / |
|
|
R Pi |
If You Blow Down Thru the Spool the Card Sticks to the Spool, Contrary to General Opinion.
portant to measure the exact pressure at each locality. It is possible to determine one's height above sea level by the read- ing of the barometer. Also the readings of the barometer show how the weather conditions are. The barometer is nothing but an instrument to measure the pressure of the atmosphere. Obviously our Fig. 18-A represents a crude barometer. Its great disadvantage is that when carried about from place to place one is likely to spill the mercury. An improved form is shown in Fig. 18-B. The same tube used in A is sealed again, bent at the open end and filled with mercury. The air pressure acting at the open end supports a column in the closed end, so th^t th. height in the closed section is thirty inches above the level in the open end. In the commercial form a scale (yard stick) - attached so that one can read the levels directly. This form can be carried about more freely without danger of spilling the mercury but is nevertheless cumbersome and inconven- ient. The aneroid barometer is much more compact (it can be had even as small as an ordinary alarm clock). Instead of mer- cury to be acted upon, this instrument em- ploys a diafram which is moved in and out by the atmospheric pressure just as the
A Simple Air Thermometer — Utilizes the Ex- pansion of Air on Heating to Vary the Height of a Water Column.
sheet elastic was in experiment 21. The motion of the diafram is magnified by a system of levers and is communicated to (Continued on page -47)
26
THE ELECTRICAL EXPERIMENTER
May, 1917
Wireless Telegraphy
General Superin
THE history of wireless telegraphy repeats once more the old story that is so often connected with great inventions. The world be- ing possest of a new scientific principle, many minds in many parts of the world are simultaneously bent upon its practical application, with the result that the fundamental principle finds embodi- ment in various methods of accomplishing a similar purpose. The startling nature of the discovery of electric waves was bound to give rise to unprecedented activity in the field of experimental investigation, and such experiments as were particularly successful were bound to prompt investi- gators to seek patent protection on their modifications, and this in turn gave rise to several systems of radio-telegraphy.
A voluminous list of names could be giv- en of those who have contributed to the advancement of radio-telegraphy in regard to both theory and practise. Among the best-known American investigators are Fes- senden, Shoemaker, de Forest, Clark, Stone and Massie. Each of these men f as devised a system which bears his name. In Eng- land the work has been carried on by men
By E. B. PILLSBURY tendent, Marconi Wireless Telegraph Company of America, New York
of such unqualified dis- tinction as Lodge, Alex- ander, Muirhead, Flem- ing, Thomson and Ruth- erford. Slaby, Arco and Braun are the names best known in Germany. The French are represented by Ducretet, Branly, Rochefort and Tissot, be- sides other men of lesser fame. Italy has contrib- uted largely to the sub- ject, principally thru Marconi, Bellini, Tossi and Righi. Denmark is represented by Poulsen. Spain, Austria, Bel- gium and Argentina have all produced systems which have been more or less used in their respect- ive countries. The Jap- anese have also devised a system that successfully stood the test of service in the Russo-Japanese War.
Interesting View of a Bank of High-speed, Automatic Sending Keys and Bus-bar Connections in a Typical High-power Marconi Radio Station.
Gigantic Oscillation Transformers and Tuning Inductances In Marconi Trans-oceanic Wireless Transmitting Station.
The development of. the art in the various countries has been car- ried on largely by repre- sentative investigators, and in many instances the governments have adopted a system ex- ploited by their subjects. The United States gov- ernment, however, has experimented with most of the prominent systems offered, and, as a result, the army and navy equip- ments are comprised of quite a variety of appa- ratus of different inven- tors.
Wireless telegraphy was the subject of ear- nest experimentation as
early as 1838, but, as far as the public mind is concerned, the science began when Mar- coni sent his first message across the At- lantic from Cornwall to Newfoundland in 1902. This wonderful accomplishment had so much of the spectacular element in it that wireless telegraphy and Marconi be- came famous at once and, measured by re- sults, he has eclipsed all other inventors.
Marconi first interested himself in the problem of wireless telegraphy in 1895. In the following year he took out the first pat- ent ever granted in England for a practical system of wireless telegraphy by the use of electric waves. In 1897 he successfully communicated across Bristol Channel, a distance of nine miles. At the invitation of the Italian government, Mr. 'Marconi sub- sequently went to Spezia, where his system was put to practical test on board two It- alian battleships. A station was erected on
'International Cable Register Supplement.
May, 1917
THE ELECTRICAL EXPERIMENTER
27
land, and the ships were kept in constant telegraphic communication with the shore up to a distance of twelve miles. Return- ing to England he made further experi- ments and succeeded in communicating be-
Looking Up One of the Towering 450- Foot Tub Masts, Which Support the Immense Aerials Used the Ocean-wide Signaling Spans.
tween Salisbury and Bath, a distance of thirty-four miles.
Mr. Marconi came to the United States in 1899, in connection with the America yacht cup race between Columbia and Shamrock I, In the same year a number of ships of the British navy were equipt with his apparatus. Early in 1901 tele- graphic communication was established be- tween two points more than 250 miles dis- tant. In February, 1902, he received, on board the steamship Philadelphia, in the presence of the ship's officers, good mes- sages on a recording tape when at a dis- tance of over 1,500 miles from the trans- mitting station. In December, 1902, he es- tablisht a station at Cape Breton for trans- atlantic service, and maintained communi- cation with the Cornwall station at Poldhu, transmitting inaugural messages to the King of England and the King of Italy, the London Times . and others. A year later, during the voyage of the steamer Lucania, Mr. Marconi maintained commu- nication between the ship and the Marconi station at Glace Bay, in Cape Breton, and Poldhu, in England, and a newspaper was publisht and issued daily to each passenger. A powerful station at Clifden, on the west coast of Ireland, was opened early in 1907, by means of which public communication across the Atlantic was establisht, which has been maintained ever since.
The importance of wireless equipment of
sea-going vessels has been recognized by all nations, the United States law requiring two licensed operators on any ship carry- ing fifty or more persons and sailing be- tween ports 200 or more miles apart. It is estimated that upward of 5,000 ships are now equipt, and a large number of freighters car- ry wireless for their own pro- tection, altho not required to do so by law. In fifteen years wireless has placed to its cred- it the saving of thousands of lives and property valued at several millions of dollars. It is an inestimable boon to man- kind that we can go to sea with the knowledge that we are kept in touch with home and can summon aid in case of disaster by means of the S. O. S. signal.
Radio-telegraphy is a most potent factor for naval, mili- tary and airship use in the pres- ent war. On July 30, 1914, five days before the actual dec- laration of war, the English fleet, which had just left Port- land, was recalled by wire- less ; and on August 4, 1914, Germany flung around the world on its chain of wireless stations this vital message to its mercantile marine : "War declared on England ; make as quickly as you can for neutral port." This first dispatch un- questionably saved Germany many millions of dollars of property and secured for pos- sible future use a fleet of pas- senger and cargo boats which may yet play a great part in her recovery from war's rav- ages.
As long distance wireless rang up the curtain on the greatest war the world has yet witnessed, so it has continued to play a great part therein. One of the most striking points in connection with wireless, which has been developed by the war, is that public attention has been directed upon it as never before, owing to the fact that so much of the official communications, particularly German information, has been brought to the notice of newspap_er readers thru this medium, owing to obstruction of the German cables.
ular Steel to Bridge
One of the objections made against wire- less telegraphy is in regard to the possi- bility of interference between various sta- tions and the confusion likely to arise when a number of stations are simultaneously operated in the vicinity of one another. Altho this confusion does rarely arise in practise with proper up-to-date stations and apparatus, yet even with the old instruments when it did occur it was not by any means such a serious matter as generally appeared to the imagination of the public. In most countries the operation of wireless tele- graph stations in regard to ship and shore communication is subject to judicious rules tending to prevent mutual interference. It is well known that without proper organi- zation and discipline,, serious difficulties due to interference would occur with the great majority of ordinary land wire tele- graphs which work several offices by means of a single wire. In the case of wireless telegraphy it is often an advantage that any station should be able to pick up a mes- sage which may not be actually addrest to it, as, for instance, in the case of a ship in distress calling for assistance. The most practical method of isolating any particular receiver so as to make it sensitive only to signals coming from a certain station lies in the principles of resonance; that is, to tune the sending and receiving circuits in exact correspondence.
When the war broke out a German com- pany had high-power stations in commu- nication between Sayville, L.I., and Nauen, Prussia (3,262 miles), and between Tuck- erton, N.J., and Eilvese, Prussia (3,383 miles). In order to protect our neutrality the American government took over these stations and is now operating them in the interests of the owners.
The government has erected a high-power station at Arlington, within sight of the Capitol at Washington, with a radius of 3,000 miles under ordinary conditions. It represents the first step of the Navy toward the establishment of a great chain of high- power wireless stations to girdle the earth and bring the Navy Department into direct communication with the fleet thruout the length and breadth of the seas. Unless a war vessel be in the Arctic, Antarctic or Indian Oceans, it will be at all times with- in the range of one of the seven contempla- ted stations, the other six of which are to be located at San Francisco, Honolulu, Ma- nila, Guam, Panama and Samoa.
From the Arlington station messages can be sent to vessels stationed beyond the {Continued on page 77)
500-horsepower Steam Turbines and Generators in Marconi Trans-oceanic Radio Station.
28
THE ELECTRICAL EXPERIMENTER
May, 1917
San Diego — Largest Radio Station in U. S.
By J. BASSETT
THE new $300,000 wireless telegraph station at San Diego, Calif., has just been completed and officially put in commission January 26, 1917. It is the largest and most powerful radio station in the western hemisphere. It is capable of flashing messages 12,000 miles. Messages
three 100 kilowatt transformers 2,800 pounds each.
Establishment of a distant control sys- tem will enable operators at any naval ra- dio station on the Pacific Coast from Point Loma to Alaska to operate its sending in- struments. This is accom'plisht by a sys- tem of land telegraph lines. The radio apparatus is what is known as the Federal Poulsen arc trans- mitter and was manufactured by the Federal Telegraph Co., of San Francisco. The Poulsen arc employs a direct current arc of 600 to 1,000 volts, burning in a closed chamber of hydrogen, the terminals being placed at right angles in a powerful magnetic
View Above Shows Mission Style Operating Building and Fan-Tail Lead-in at Powerful New
U. S. Radio Station, San Diego, Cal.
At Right: — Looking Up One of the Gigantic 600- Foot Latticed Steel San Diego Wireless Towers. Below: — Concrete and Porcelain Base Support for Insulating the Steel Tower Legs.
from the British high seas fleet cruising in the North Sea, from the high powered German plant at Berlin and from Aus- tralia have been intercepted thus far.
The three 600 foot aerial towers form a triangle. They contain one million pounds of fabricated steel and are the largest radio towers in the world. The towers are triangular in section, 150 feet in width at the base and eight feet at the apex. They are placed 1,100 feet apart. Porcelain insulators imbedded in concrete form the base of each leg of the towers.
The receiving room is absolutely sound proof, the walls and floor being padded with asbestos. There are four distinct and complete controlling sets installed in the receiving room, enabling any one of the four operators or all four at once to send and receive messages.
The aerial or antennae weigh 16 tons and has a sag between towers of 100 feet. The aerial is twice as large as that strung from the Eiffel Tower in Paris. The helix is 14 feet in diameter and 11 feet in height or 9 feet higher than the helix used in ordinary naval and commercial stations.
The generator weighs 60 tons and the
field. Electric current for the radio set is furnished by a 200 kilowatt — 1,000 volt direct cur- rent generator, driven by a 300 horsepower 2,200 volt 60 cycle in- duction motor.
Six buildings costing $39,590, in mission style architecture, form the quarters for those on duty. Here we find a large, airy dormitory, gymnasium and well- furnished library.
A silver plated telegraph key was pre- sented to Commander Hooper after he had dispatched the first message. The fol- lowing inscription was on the key : "High Power Radio Service, First Message, Com'd'r S. C. Hooper, Jan. 1917, San Die- go." At exactly 11.02 January 26, 1917, Commander Hooper called the station at Arlington and sent this message from the Mayor of San Diego to Secretary J. Daniels :
"In behalf of the citizens of San Diego I have the honor of extending to you the season's greetings and their good wishes and congratulate you upon the completion at San Diego of the world's most power- ful radio station. Space has been com- pletely annihilated and the Atlantic and Pacific seaboards are as one."
Arlington acknowledged the message at 11.05 o'clock. It was immediately trans- mitted by telephone to Secretary Daniels. His reply was returned at 11.18. It was thus :
"Your greetings and congratulations much appreciated. The navy department rejoices with San Diego that the comple- tion of the new radio station at San Diego
places Washington in closer touch with the Pacific Coast and particularly with the navy's larger development at San Diego. It must be gratifying to California to know that the apparatus installed is the product of a California company."
This was followed by a message from Congressman Kettner. It was as follows : "Washington salutes San Diego, first port of call by wireless. Felicitations extended thru you to people on completion of the greatest radio station in the United States made possible by your esteemed friends, Secretary Daniels and Admiral Griffin."
It was answered by Howard Veeder, vice-president of the Federal Telegraph Co., as follows :
"Please accept the felicitation of the Federal Telegraph Co. and myself person- ally upon the successful opening of this great radio station. It is a g%eat pleasure to our company that the first example of this most remarkable advance in the ra- dio art, which has been developed by us in San Francisco should be installed in San Diego, a sister city."
The radio plant is located in a section called Chollas Heights, ten miles from the business center of San Diego, on an elevation of land, reached by auto.
U.S. RADIO INSPECTORS USE CODE MACHINE IN TESTING APPLICANTS.
All applicants for U. S. Government Radio Operator's License must pass a test in receiving messages in the tele- graphic code, i.e., in the form of dots and dashes. The accompanying illustration shows a new complete automatic tele- graphic code transmitter, known as the Omnigraph, complete with high-note buz- zer and exciting batteries, which latter are contained in the base of the cabinet. The various discs, which are properly notched on their periferies to correspond with the dots and dashes of the different letters of the alphabet, are placed one above the other on a rotatable drum or plate, which is driven by a strong spring motor provided with a suitable governor, in order that the discs may be caused to rotate at any desired speed.
The toothed disc makes contact with a special light spring brush connected with the high-note buzzer circuit. Thus, as the discs slowly rotate, the buzzer circuit is made and broken in accordance with the long and short notches on the edges of the discs.
This instrument has been used for a number of years by the government officials in examining applicants for Radio Opera- tor's License and has been found very sat- isfactory. The messages may be signaled with this apparatus at any speed from 12
Automatic Code Apparatus Used by U. S. Radio Inspectors in Examining Applicants for Operator's License.
words up to 30 words, or more, per min- ute, thus giving it a wide range of useful- ness.
A large variety of code disc are available and the machine may be set up to give dif- ferent code combinations as often as de- sired.
May, 1917
THE ELECTRICAL EXPERIMENTER
2<>
WIRELESS OUTFIT ON MOVING VAN TRACES MESSAGE.
After a search of three months for an The accompanying photographs show the amateur wireless operator who sent out long distance, undamped wave receiving unsigned "SOS" messages in the neighbor- set owned by Harvey L. Gamer, Electrical hood of New York and caused great an- Engineer of Omaha, Neb., with which the noyance to the New York Navy Yard and navy vessels the feder- al authorities recently arrested William F. Eckoff, sixteen years old, who had a wireless station on the roof of his home in Brooklyn.
When the messages were first heard there were reports in ship- ping circles of submarines operat- ing near New York. After sev- eral of these calls stations near- by recognized them as the work of an amateur. The New York Herald's wireless station worked ■with the operators at the New York Navy Yard in an effort to locate the station. The log at the Herald's wireless station shows that these distress messages were sent at all hours of the night. The mysterious operator used the calls of the Navy Yard and naval vessels.
Louis R. Krumm, chief radio inspector of the Department of Commerce, engaged a moving van and installed in it a small wireless set which could detect messages within the radius of only a block. Operators had traced the messages to Brooklyn, and, with the moving van, Mr. Krumm went about Brooklyn un- til he arrived in front of the Court Street house.
It is alleged that Eckoff used a United States code signal on the night of January twenty-first last, sending an "SOS" call which which was picked up by the Herald station and relayed to t e super-dreadnought Ari- zona at the New York yard.
Eckoff was arraigned before United States Commissioner Louis Bick and ad- mitted he had been sending messages, but asserted that if he had used the United States code he had done it innocently, for he did not understand the code thoroly enough to commit a nuisance.
The efficiency of such portable radio sta- tions has been markedly improved in re- cent years by the advent of spiral aerials.
An Exceptional Amateur Radio Station
The amplification feature is obtained by the use of inductances and capacity in the wing circuit of an Audiotron, then a further amplification with two ordinary
Above: — General View of Ex- tremely Efficient Experimental Radio Station Owned by Harvey L. Gamer, of Omaha, Neb. Note Phonograph at Right of Photo; the Signals are Recorded on it.
Upper Right View Shows the Well Designed Antenna Used With the Apparatus Here Illus- trated.
Lower Right: — Close View of 15,000 Meter Precision Loose Coupler and Audion Tuning In- ductances. An Engineer's Idea of How an Amateur Station Should be Built.
German Stations OUI, (Hanover), POZ, (Nauen) and the Hono- lulu Station KHL, are easily heard.
Some of the stations in the United States, WSL (Sayville), and especially WGG (Tuckerton), when the Goldschmit alternator is used, come in so loud that the signals can be transmitted over the telephone to any part of the city or vicin- ity. Also wax phonograph records have been made with a special recorder, as shown in the photograph.
Audions and their respective coils and cir- cuits as well as a micro-phone arrangement leading to the recording machine.
The large loose coupler was designed to tune to wave lengths up to 15,000 meters when used with this particular aerial sys- tem.
SECRETARY OF COMMERCE SUSPENDS ISSUING OF LICENSES
Issuing of licenses for amateur wireless apparatus was suspended on March twenty- seventh by Secretary Redfield. Virtually none of the amateurs have sending equip- ment, so the military and naval authorities have not considered them a source of im- mediate danger, but Mr. Redfield decided that no more should be licensed for the present. Sending wireless plants are under the strictest possible surveillance now, and if a state of war is declared efforts will be made to locate apparatus of every descrip- tion.
Many of the amateurs now licensed by the Government belong to the Navy radio reserve and will be called upon to perform certain duties in war.
Uncle Sam's Radio Inspectors Find it Difficult at Times to Accurately Locate and Run Down Stations which Disobey the Law, but a Radio Set and Aerial Erected Inside an Auto Van
Helped to Solve One Problem.
TO TEACH GIRLS WIRELESS
At a meeting of the National Special Aid Society recently, a school offering a course in wireless telegraphy for young women was organized. Instruction will be given at the society's headquarters, 259 Fifth Avenue, New York Citv.
Miss Daisy Florence, chairman of the new branch, urges that all young women who would like to take up this class of work send in their applications. E. T. Bicak, a New York radio expert, has been retained and will have entire charge of the classes. This new department, the society says, is the first of the kind.
30
THE ELECTRICAL EXPERIMENTER
May, 1917
How the Audion Repeater Repeats
A Twentieth Century Fairy Tale, Wherein the Mystery of the Audion Relay Is Explained for the Benefit of Radio "Bugs" of All Ages — From 9 to 90
YOU all remember what you learned at school about matter being made up of molecules and molecules being made of atoms beyond which matter is indivisible. That is, with a meat axe, you can divide a sub- stance into small pieces like hash ; and with a microscope and hair-splitting equipment you can divide a substanc into pieces smaller than the naked eye can distinguish ; after that by means of chemicals you can separate molecules from eac' other altho you can't see them, even with a microscope ; then with more chemicals you can separate the atoms from each other, but beyond this no treatment has any effect ; at least that's what we learned at school and that effectually proves that there are no such things as fairies or daemons.
But now come our highbrows with an- other story. Mind you, you don't have to believe it. They say that atoms may be made to throw off par- ticles like a small boy throwing gravel at the passing trolley car, only the kiddies do it voluntar- ily for the fun of the thing, whereas the atoms must have some provocation ; for example, if they get good and hot they cqmmence to throw gravel like a, terrier pup at a woodchuck hole.
Now, all ordinary people know how to take such talk as this. It's just like Arabian Nights and Dr. Cook stuff about stones talking and mountains splitting open, or the beautiful stripes around the North Pole. Nevertheless one of our cloister experts will draw you a picture like Fig. 1, to represent the in- terior of a vacuum bulb repeat- er, and says that "F" is a fila- ment, which is heated red hot by the electric current from bat- tery "A," and "P" is a plate which is connected to the out- going line. In the space be- tween the filament and the plate is the piece of picket fence "G," which is connected to the incoming line, and this gridiron is what puts the fire in amplifier.
To make the matter perfectly clear, as a fairy tale should be, look at Fig. 2, where7 instead of a filament there is an iron step- ladder on which you can see a lot of atoms, or daemons — it doesn't matter which you call them — and on the other side you see the plate as in Fig. 1. Be- tween these two is an ordinary window blind with slats which are all operated together by the usual center stick. Now, suppose a strong electric current is past thru the iron stepladder so that it heats up like the filament in Fig. 1, then each little daemon gets as mad as a hen on a hot griddle and begins to throw pebbles at the window shutter. What's that ! Where do they get the peb- bles? Say, this is a fairy story and you must not ask foolish questions. Lord Kelvin thought the atoms were made of these pebbles or corpuscles, and that these pebbles or corpuscles were, in fact, electricity itself, hence the name electrons. In other words, matter is made of electricity and electricity is imponderable; therefore, there is no matter, and if there is no matter,
it doesn't matter, and we should worry.
If while the daemons are bombarding the shutter we should open the slats, enough pebbles would go thru and strike the plate to make a noise like a hailstorm on a tin roof and the number that strike the plate would be in proportion to the amount the slats are opened. Therefore, if the slats are opened and closed in time with music it would be possible to play a tune on the plate, and if each electron carried a little bit of electricity with it, the effect would be like a current from the stepladder to the plate, and this cur- rent would pulsate, increasing when the slats are opened and decreasing when they are closed.
This is just what happens in the vacuum repeater bulb shown in Fig. 1. The filament is heated red hot by the current from battery "A," and" at this temperature mil-
The Above Illustrations Help to Make Clear in the Most Simple Manner, the Action of the Audion — That Mysterious Radio-elec- trical Device. Considering the Top View, Just Imagine That the Host of Daemons on the Ladder (the Filament) Start Throwing Pebbles Thru the Movable Slats (the Grid) at the Target (the Plate). How Do They Get the Pebbles? — Oh! Well — Read This Remarkable Tale.
lions of corpuscles or electrons are thrown off. The electric current is not necessary to cause this ; the same thing would hap- pen if it were heated by a gas flame. These electrons are considered to carry charges of negative electricity itself. Here again we should worry, because the result is the same, no matter what anyone thinks ; because a current actually does flow from the filament to the plate.
You all remember that unlike polarities of electricity attract each other while like polarities repel, and so if the gridiron is made negative to the filament the electrons will be repelled by it and very few will get thru between the slats; in fact, if the slats are too close together no electrons at all will get thru to the plate. The ef- fect would be the same as tho the slats in Fig. 2 were entirely closed.
It is generally known how the sound waves produce electrical pulsations in a telephone line; and you have only to im- agine these pulsations of current coming to the induction coil "T" at the left side of Fig. 1. These pulsations are, of course, very weak because of the long line over which they have traveled and the purpose of the repeater is to amplify or strengthen these pulsations.
Now, while it takes considerable power to open and close the slats of a window blind, especially if you painted them yourself last spring, the operation of the electric shutter is frictionless and even the weak impulses of speech transmitted over 500 miles of line are sufficient to give the desired results so that as each increase or decrease of current raises or lowers the negative potential of the grat- ing "G," more or less electrons each with its infinitesimal charge of electricity get thru from the red-hot filament to the plate and give the exact same, but much stronger, impulses of current from the plate to the induction coil at the right side of the picture, and so out on the line for another 500 miles, the amount ■ of additional pep put in the impulses, depending on the strength of the battery "B."
Now you are probably won- dering why this apparatus is put in a glass case. The reason is that the scheme will only work in a very good vacuum because a clear space is necessary for the electrons to travel in. You must remember that everything, even an invisible gas, is com- posed of atoms, so if there was air or any kind of gas in the space between the filament and the plate, the electrons would bump the atoms of the gas while the daemons might put a good many across, the number would not be constant from minute to minute, depending on how successful they were in dodging the atoms and the re- sult of this would be a jerky current which would entirely mask the telephonic pulsations. Therefore, in order to obtain the required accuracy of con- trol of the rate at which the electrons strike the piate, it is necessary to pull out of the space between the filament and the plate every loose atom that it is physically pos- sible to get hold of. ,
This is so important that our highbrows have developed an extremely interesting method of inducing daemons themselves to call the game when the space is cleared, but that is another story to be told when you have recovered from this one. — '"W.E.N."
May, 1917 THE ELECTRICAL EXPERIMENTER 3
The Ionic Radio System and Theory of Ionic Tuning
By Otto E. Curtis
Associate Member ot the Institute of Radio Engineers
THE physico-chemical science per- taining to the elemental constitu- tion of matter and the relation of the ion to the organization of matter dates back to the time of Thales of the so-called "early school of Ionic Philosophers," which came into exis- tence about six centuries ii'.C. Thales, and
The Apparatus Used in Ionic Tuning of Radio Messages According to the Method of Mr. Curtis, as Described Herein.
the other scholars of this time, made little real progress toward a scientific develop- ment of the subject, altho in the light of recent discoveries many of their heretofore seemingly crude experiments and theories 'appear to have surprising significance.
For example, the ancient Alchemists of this period made many attempts at "trans- mutation," that is, at converting basic met- als such as lead into precious metals such as gold, and in connection with these ex- periments they developed theories which, while entirely too vague to lead to useful conclusions, bear similarities to the modern theories pertaining to tne transmutation or transformation of various radio-active com- positions of matter into other comoounds having different ionic groupings. Howev- er, the secrets pertaining to the part played by ions in the constitution of matter have not, at least up to the present time, been discovered and subjected to the use of man.
During the past eleven years I have been continually striving to fathom some of these secrets and it is my present purpose to dis- close one of the more important discoveries which has resulted from my investigations, this particular discovery forming the ba- sis of one of my earlier patent applications. And in order more clearly to set forth this discovery I ^hall first describe some of my experiments and the apparatus employed.
The first machine I built with the object of recording messages was completed in 1906. It consisted of an E. I. Co. "Auto- coherer" connected to a "Telimco-meter" galvanometer with contacts on the needle. Impulses received by the auto-coherer were intended to deflect the needle and close relay contacts, but they did not do so and this machine failed to operate. This was an attempt to find a self-restoring coherer, but, while the coherer was self-restoring, it was not sufficiently responsive to current of the magnitude which I then employed.
A later machine, completed November 25, 1916, and shown in the accompanying photograph, follows the same original idea but its special parts have been much more highly developed. It receives perfectly the time from Arlington at a distance of 200 miles, ticking it off clearly on a buzzer and making tape records of the same, but as yet
* Copyright 1917 by Roberts, Roberts and Cush- man. Exclusive rights to The Electrical Experi- menter.
it is not quite fast enough to copy actual commercial messages. It was originally de- signed as a chemically tuned call-bell for a wireless telephone, for which it works ex- cellently. (This process of chemical tun- ing or Ionic tuning will be explained fur- ther on.)
The apparatus illustrated in the photo- graph is made up as follows : The device shown in the upper left-hand corner is a Multi-audi-fone pocket wireless set. The wooden base in the lower left-hand corner carries two of my ionic detectors construct- ed as shown in Fig. 5, and as hereinafter described, the one on the left comprising a zincite crystal and the one on the right a silicon crystal. The rectangular instrument in the center is a Weston relay, which com- prises an extremely sensitive galvanometer having a very short needle which, when de- flected, contacts with one of the platinum- iridium points disposed on opposite sides of the needle. The instrument on the right is an E. I. Co. polarized relay of 1,000 ohms resistance which may be connected to an indicating or recording or other device such as a buzzer, tape recorder, motor, lamp or explosive device.
In the accompanying figures, Fig. 1 shows the circuit connections for the apparatus shown in the photograph, the various instru- ments being diagrammatically illustrated in the figure in the same relative positions as in the photograph for the sake of clear- ness. The antenna 1 is connected to ground 2 thru the primary 3 of the Multi-audi- fone set, the secondary 4, of which is ar- ranged to be connected to the Weston re- lay by means of double throw switch 5 either thru detector 10 or thru detectors 7 and 8. When the switch 9 is to the left,
Diagram of Connections Possible to Realize the Claimed. Besides,
the zincite detector 7 is connected in cir- cuit; when the switch 9 is to the right the silicon detector 8 is in circuit, the detectors
7 and 8 being connected to the secondary
4 by leads which arc not shown. The cir- cuit connections as existing when the switch
5 is in upper position, are shown in simpli- fied form in Fig. 2, reference to which may be had in following out the operation.
The alternating current of radio fre- quency received by the open antenna circuit 1-3-2 is induced into the secondary circuuit, where it is rectified by the detector 10 and conducted to the Weston relay 6. This pro- duces a deflection of the relay 6 which in turn closes the local circuit containing the polarized relay 11 and source of e.m.f. 12. This actuates relay 11, which closes the circuit thru a second source of e.m.f. 13 and the indicating, recording or power appa- ratus 14. By employing one of my im- proved ionic detectors at 10, very feeble im- pulses may be detected ; and by employing a series of relays in the manner described, the feeble impulses may be magnified to any desired extent, each consecutive relay con- trolling a heavier current so that the last circuit 11-13-14 may comprise a power cir- cuit carrying current of any strength.
When using the machine for lecture pur- poses, with the sender in the same room a "Hertz" lineal resonator is used instead of an aerial and ground, as shown in Fig. 3. This consists of two lA inch brass rods fitted on adjacent ends with brass balls of equal size and separated a short distance, this distance bearing a direct ratio to the length of the spark gap of the sender. The free ends of the rods are fitted with the movable metallic plates 15. Moving these plates together with the similar ones on the oscillator of the spark gap tunes the sys- tem. This "resonator" serves the same pur-
pose as the "catch wires" used on the E. I. Co. "Telimco Coherer Set." The resonator, (Continued on page 73)
Used in the Curtis Scheme of Ionic Tuning, Whereby It Becomes Highest Efficiency in Radio Transmission and Reception, It Is It Enables the Operator to Record the Messages if Desired.
32 THE ELECTRICAL EXPERIMENTER May, 1917
Receiving Marconi 300 K.W. Spark Stations with Oscillating Audion
By SAMUEL CURTIS, Jr.
IT is a widely known fact that the Marconi Wireless Telegraph Com- pany has in operation a number of 300 K.W. spark stations, used for the purpose of handling their enormous traffic between different countries. The stations of this character which are active- ly engaged, to my knowledge, in transact- ing business at the present time, are : Clif- den, Ireland; Glace Bay, Nova Scotia; Bo- linas, California ; Koko Head, Hawaii, and Funabashi, Japan.
The wave length used in transmission ranges from 4,000 to 8,000 meters, but the most common is 6,100; this is used ex- tensively at the Koko Head and Bolinas stations.
In receiving the signals from these sta- tions, any Audion receiver capable of at- taining the wave length may be used, and it may be well to state that the undamped wave receiver described on page 575 of the December issue of The Electrical Ex- perimenter has been used in this respect with marked success. The writer wishes to state, however, that since the publica- tion of his article relative to this receiving set, a fixt condenser of .005 m.f. has been added to the circuit. This is hooked up across the telephones and high potential battery of the Audion, and by its use al- lows the bulb filament to be burned at a much lower brilliancy, and yet get strong oscillations therefrom.
It is, of course, easily possible to receive these stations on a crystal detector, but un- less an extremely large antenna is avail- able, .this cannot be accomplished over any great distance. It has been found by ex- periment that a heterodynic action on the incoming signals produces a remarkable increase in audibility, therefore making it feasible to incorporate the use of an os- cillating Audion in this respect.
The series of graphs shown in Fig. 1 clearly illustrate the character of the mo- mentary currents produced by a feebly damped wave train, in the circuits of a receiver during the process of heterodyn- ing. In graph "A" we have the feebly
The Series of Graphs Shown Above Serve to Illustrate the Character of the Momentary Currents Produced by a Feebly Damped Wave Train, in the Circuits of a Radio Receiver During the Process of "Heterodyn- ing."
damped wave train, such as is sent out by the above mentioned high-powered stations. In graph "B" we have the local or Audion oscillations, which are used in heterodyn- ing the wave train of graph "A." These
Audion oscillations are tuned to a fre- quency either higher or lower than that of the incoming wave, so that an audible note is obtained in the telephones. In graph "C" we have an illustration of the current pro- duced after "A" and "B" have coincided with, or heterodyned each other. In graph 'D" is shown the resultant current after it has been rectified. It should be under- stood that the tone of this current in the telephones is proportionate to the difference in frequency of the incoming wave, and the Audion oscillations; for instance, a wave length of 6,000 meters would have a fre- quency of 50,000 cycles. In order to get an audible note of 500 cycle pitch, we would have to have an Audion frequency or either 49,500 or 50,500 cycles. This is assuming that we are heterodyning an un- damped wave. Of course when a damped wave is heterodyned it cannot be expected that a pure note will be obtained, owing to its irregular form. In actual practise the note obtained in heterodyning the Mar- coni signals is very near the same as that obtained by using a crystal, only a little distorted.
The beauty of the use of the heterodyne reveals itself in an astonishing increase in the amplitude of the telephonic current, as illustrated in sketch No. 2. It can be seen by observation of this sketch that the mere rectification of a wave train does not in any way amplify it. Now, .if the same wave train is heterodyned, an increase in amplitude similar to that illustrated in sketch No. 2 is obtained. The reason for this is best explained by the fact that in the mere rectification of a damped wave train, only the first few oscillations are utilized, and the rest of the energy is hope- lessly wasted. In subjecting a feebly dampt wave train to heterodynic action practi- cally all of the energy is utilized, mani- festing itself in an enormous increase of audibility. To those who are more or less familiar with the action of the heterodyne, this brief explanation will suffice, but to go into a detailed description thereof would be out of the scope of this article.
It might be of interest for the reader to know that at the present time, at a cer- tain experimental station on the Atlantic Coast, signals are being received daily from the Marconi station at Koko Head, Hawaii. The receiver used is of the type described in the December issue of this journal with the single exception that an Electron Relay is used instead of the usual spheric Audion bulb for producing the os- cillations. Glace Bay, Nova Scotia, comes in with remarkable audibility, while Boli- nas, California, is read nearly as loud. The stations at Clifden, Ireland, and Funabashi, Japan, have not as yet been pickt up, but it is expected that in the near future Clifden will be copied, as this station is not nearly as far distant as Koko Head, who is read in the daytime in good weather. The aerial used at the above mentioned sta- tion has a natural period of 276 meters, and is none too elaborate.
The results made possible by the oscil- lating Audion in receiving dampt waves are not however confined to such long waves as are used by the Marconi stations. With careful adjustments and the use of low resistanced inductances, an Audion can be made to oscillate on 200 meters or less, depending of course upon the skill and perseverance of the operator.
No one can fully appreciate the efficiency of such a method of reception until he has actually used it himself. At the present time there are a number of Regenerative receivers on the market. These instru-
ments are without a doubt the peer of any- thing in their line, but for many experi- menters the price of such an outfit is pro- hibitively high, and the chances are they have to do without. One advantage, how- ever, is that these receivers are not so in- tricately designed as to make it impossible
|
1 |
\ |
||||||
Fig. 2
Graph Illustrating the Marked Increase in the Amplitude of Received Radio Signals Due to "Heterodyning" by Means of the Oscillating Audion.
for the experimenter to make one for him- self. This is being done with great suc- cess by a large number of amateurs thru- out the country. If the reader cares to take the trouble to consult page 575 of the December issue of this magazine, he will see a neat little regenerative hook-up given in set "B" of the diagram on that page. Set "A" is used for long waves, and set "B" for waves from 200 to 2,500 meters.
[We are informed by Mr. Curtis that in some tests conducted in the laboratories of the General Electric Co., at Schenecta- dy, Dr. White has succeeded in making an Audion oscillate (heterodyne action) on a wave length as low as y2 meter. Of course this requires some elaborate tuning and even more elaborate apparatus.— Ed.]
RADIO EXHIBIT AT NEW YORK AERO SHOW.
At the recent Aeronautical Exposition held in New York City, serious considera- tion was .given to radio equipments for aeroplanes and balloons. A large space was set aside for the exhibition of different types of sets, such as are used now in the European countries for directing the artil- lery from aeroplanes, for interfering with stations and for long distance communica- tion to be used by observers. Models of the different types of wireless equipments using direct and alternating current gener- ated by small dynamos which get their power from the air by means of a small propeller were shown. The Marconi Com- pany was invited to exhibit the set which was recently purchased by the Navy De- partment for hydroaeroplanes. This in- strument has one K.W. capacity and it is stated that up to 300 miles will be obtained. That is to say, the aeroplane can signal for a radius of 300 miles. The total installa- tion will come within 100 pounds. Other sets made by the Sperry Gyroscope Com- pany, De Forest Radio Telephone & Tele- graph Company; William Dubilier, Wire- less Specialty Apparatus Company, Cutting & Washington, Manhattan Electric Supply Company and Mr. A. B. Cole. The wire- less operators were supplied by the East Side Y.M.C.A. under the direction of Mr. Boehm.
May, 1917
THE ELECTRICAL EXPERIMENTER
33
Distributed Capacity and Its Effect
D
capacity
ISTRIBUTED capacity may be defined as the capacity existing between turns of a helical coil. It may also exist in straight con- ductors where the electrostatic s between the conductor and the
Theoretical Relation of Distributed Capacity to Inductance Coils. The Effect Is the Same As if a Number of Small Condensers Were Connected Across the Turns on the Coil.
earth, or between two adjacent conductors.
It can be shown by actual experiment that a difference of potential exists be- tween adjacent turns. This potential dif- ference creates an electrostatic field and energy is stored between the conductors.
A condenser is a device which stores electrostatic capacity. It is evident there- fore that a condenser is formed, the plates of which are the adjacent conductor turns. The capacity is stored in the space between each turn of the coil and over all of the turns, therefore the capacity is distributed over the entire conductor.
Referring to Fig. 1, it will be seen how distributed capacity is related to coils. In- creasing the length of the coil, increases the distributed capacity as it is seen that the number of condensers are increased. Since increasing the number of condensers in parallel increased the capacity, therefore we may consider all the parallel condensers as one large capacity shunted across the inductance, as indicated in Fig. 2.
When capacity and inductance are linked, in a circuit we have an oscillatory circuit, and the period of vibration of such a sys- tem is directly proportional to the square root of the product of the inductance and capacity multiplied by a constant Ex- pressing the above in an algebraic form we have:
n = , 4 ■ (l)
Here n = period of vibration of the sys- tem. The wave length of the above cur- rent is,
A = 59.6V£~c W
Representing the Relation of Distributed Capacity in a Coil (Fig. 2) and the Voltage and Current Distribution in Inductance Coils (Fig. 3).
where L and C are the inductance and ca- pacity.
It is evident therefore that since the coil
By SAMUEL COHEN
has distributed capacity that the coil is an oscillatory circuit in itself, and it was found by actual experiment that when properly excited by a high frequency current, it will oscillate, the period of which depends upon the magnitude of the units of inductance and capacity.
The true wave length of a circuit con- taining a large inductance and shunted with a capacity is not the same when calculated with formula (2) but the exact wave lengths will be as exprest in the follow- ing relation :
a = 59.6 -s/L(C +CX) <3>
Where C is the capacity of the shunted condenser and to it we add the distributed capacity of the coil Cx. Solving for Cx we have :
C«= A~LC' (4)
Calling the total capacity Ct equation (4) becomes :
Cl=(59^Z (5)31
It has also been found by actual experi- ment that whenever a large coil was ex- cited by radio frequency current it will
Primary, str/fc/) '
KSmk/) 0.0 ooint --J^^S^w^ off 'point r>
Fig. 5. Dead-end Elimination Switch for Loose Couplers Which Has Proven Very Effective in Reducing Distributed Capacity in the Windings.
oscillate in its own period just the same as a coil shunted with a condenser and excited. The current and voltage relation of this coil is exactly the same as for a Hertz oscillator, where the current value is a maximum at its center and minimum at the ends, while the voltage is maximum at the ends and minimum at the center. Fig. 3 shows grafically this relation of the coil.
The best means for determining the dis- tributed capacity is by actual measurement. The essential instruments necessary for this kind of work are calibrated inductance and capacity which may be obtained from a wave meter, a high frequency buzzer and an additional condenser. The instruments are connected as indicated in Fig. 4. The coil, whose distributed capacity is to be de- termined, is placed in a single loop of wire L, Fig. 4, which is excited by the buzzer, Placing the wave meter inductance L2 near the excited circuit the condenser C2 is turned for indicating resonance. When the point of resonance is obtained the period of vibration of both circuits are the same
T = T. Substituting the observed values in the equation,
Cd =
(5)
Arrangement of Apparatus for Measuring the Distributed Capacity in a Coil. A Buzzer Serves for Excitation of the Coil Under Measurement, While a Wave Meter Is Used to Ascertain the Wave Length of the Coil.
Where L2 = the inductance of wave meter coil in centimeters. C2 = capacity of condenser at point
of resonance in m.f. Li = inductance of coil, the distri- buted capacity of which to be found. It is advisable before starting to meas- ure the distributed capacity of a coil, to determine before-hand the magnitude of the figures so as to enable us to procure approximately the proper inductances and capacity in the wave meter circuit. It