Part 5

The device is designed on a new principle, and has a very sharp control of the motor revolutions. Simple means are provided for easily verifying the continuity of the motor control.

These fork motor units will control any number of motors of any size, at any distance, and on moveable or stationary platforms.

[Illustration: [Photographs]]

The Jenkins Picture-Strip Machine

In the transmission of news, market reports, etc., as a continuous process a long strip of paper of typewritten copy is put into this machine, and the blacks and whites of the letters and figures falling on the light sensitive cell open and close a C. W. broadcast or wire circuit; which at distant points is translated back into light and recorded on a long strip of photographic paper.

This can be a continuous process if the sending strip is added too from time to time, and the receiving photographic strip of paper, as it is exposed, passes continuously through a developing, fixing, washing and drying bath. This process might be required by the conditions of service. A white strip and an electric pen may be used instead of photo paper.

In the sending machine the rotating prisms sweep the image of the typewriter line across the light sensitive cell; and the strip is moved longitudinally by winding on a drum.

In the receiving machine the strip is drawn along while it is curved around a rotating cylinder inside which the modulating light is located, turned off and on by radio. A corona glow lamp is preferably employed with the photographic paper.

[Illustration: [Photographs]]

Jenkins Duplex Machine

The Jenkins duplex cylinder type of machine was designed for simultaneously sending and receiving photograms, letters, maps, drawings, etc. The motor runs all day long, like an electric fan, in control of the vibrating fork. The right hand (glass) cylinder sends; and the left hand cylinder receives. The messages are put on and taken off without stopping the machine, and without one function interfering with the other.

The machine may be used on radio or on wire, and is an easily operated machine, the perfect functioning of which can be determined by a glance at the perforated rotating disc illuminated by the synchronizing signal lamp.

It is believed to be the first duplex two-way service machine ever built, and is complete as shown, except for the batteries and the radio receiving set, which latter may be any standard set which will operate a loudspeaker.

The illustration shows a machine in which a picture transparency and a sensitive cell is used at the sending cylinder; and a high speed lamp and photographic paper at the receiving cylinder.

[Illustration: [Photographs]]

“Talking Machine” Photograms

The spring driven machine illustrated is probably the simplest device possible for the experimental study of transmission of pictures and picture messages by radio or by wire. A conducting ink or pencil line on paper and put on one cylinder (or an insulating coating cut through with a stylus) over which the sending point rides for sending; and an electrolytic bromide (or photo) paper on the other cylinder under the receiving pen for receiving; the contact points being attached to the sending and the receiving sets respectively.

The upper illustration shows a machine electrically driven and equipped to transmit and receive handwritings, maps, sketches, pictures, etc., of an area of about 5 × 7 inches. The sending is from pencil lines on paper, the reception on electrolytic paper.

The machine is also made with a glass cylinder to send from a picture transparency, and to receive on photographic paper. It must, therefore, be used in a dark or subdued lighted room to receive.

Each machine is capable of the very highest quality of work of its particular kind, and is simple and easy to operate.

[Illustration: [Photographs]]

Radio Vision

The machines here shown are the laboratory models used in the development of Radio Vision and Radio Movies for the reception in the home of broadcast studio performances, i. e., dancing girls, public speakers, pantomime, marionettes, motion pictures; and, by remote control, outdoor events, sports, etc.

The lower illustration shows a 10″ disc rotating in front of a prismatic ring, synchronized by a variable speed of the motor. The light is in the round box at the top of the standard behind the lens carrier, and shines through lenses and prism (onto a picture screen) as they pass, the light fluctuating in value with the incoming radio signals to make up a complete picture every one-sixteenth of a second.

The upper illustrated mechanism differs from the lower one in that it has a second overlapping prism for optical correction.

The casing enclosing the mechanism is not very large, and contains, besides the radio vision mechanism, the radio receiving set, and a loudspeaker, so that an entire opera in both action and music may be received.

[Illustration:

The prismatic ring can be rotated to follow any moving object; e.g., a motion picture film; or if fitted with a high-reading automobile speedometer the speed of an airplane or dirigible can be read directly off a dial by the navigating officer. ]

[Illustration: [Photographs]]

[Illustration: glowing filament offset hollow cylinder filled with light NEW LIGHT SOURCES FOR RADIO vibrating gold leaf electroscope for blinking a constant light source spark plug light source]

glowing filament offset

hollow cylinder filled with light

NEW LIGHT SOURCES FOR RADIO

vibrating gold leaf electroscope for blinking a constant light source

spark plug light source

[Illustration: [Drawing]]

[Illustration:

The rotation of the disc _A_ carrying lenses _b_, _c_, _d_, etc., sweeps the image of the light source _C_ across the screen _F_ in a horizontal direction, while line displacement in a vertical direction is effected by reason of the changing angle of successive prism elements. ]

[Illustration:

The rotation of the disc _A_ carrying lenses arranged in a spiral causes the light _L_ to sweep across the screen _M_. A revolution every sixteenth second gives a motion picture screen effect. ]

[Illustration:

RADIO MOTION PICTURE MECHANISM

The rotation of the drum _A_ carrying the lenses _b_, _b′_, _b″_, etc., causes the image of the light source _S_ to sweep across the screen _Y_ in two directions. A complete rotation every sixteenth of a second is motion picture speed. ]

[Illustration:

Radio Vision hook-up circuits. _A_ is the light cell. The upper circuit puts a “chopper” frequency onto the radio carrier wave by the inductive coupling.

The lower diagram shows an intermediate frequency oscillator to be controlled by a light cell (not shown), the intermediate being put on the carrier wave. ]

Historical Sketch of Jenkins Radio Photography

1894. Jenkins publishes article on transmission of pictures electrically with illustration of proposed apparatus.—_Electrical Engineer, July 25, 1894._

1913. Proposes another mechanism, for “Motion Pictures by Wireless.”—_Motion Picture News, September 27, 1913._

1920. Reads paper on the Prismatic Ring, a new contribution to optical science (an essential element in transmission of radio pictures).—_Transactions Society Motion Picture Engineers, Toronto Meeting, May, 1920._

1922. Sends first radio photograph; sent from a photograph, and received photographically; and predicts motion pictures by radio in the home.—_Washington Evening Star, May 19, 1922._

1922. Sends photographs by telephone wire of American Telephone & Telegraph Company, through his desk telephone, from 1519 Connecticut Avenue (Washington) to Navy Radio Station, NOF, at Anacostia, D. C., and there broadcast. The signals were picked up and recorded on a photographic plate at 5502 Sixteenth Street N.W., Washington, D. C., in presence of Commander A. Hoyt Taylor, of the U. S. Navy, and J. C. Edgerton, of the Post Office; October 3, 1922.

1922. Makes official demonstration of his radio transmission of photographs for Navy officials December 12, 1922, in presence of Admirals S. S. Robison and H. J. Ziegemeier, Captain J. T. Tompkins, Commander S. C. Hooper, Lt. Commanders E. H. Loftin and H. P. LeClair; the report of which was later released for publication.—_Washington Evening Star, January 14, 1923._

1923. Sends radio photographs of President Warren G. Harding, Secretary Herbert Hoover, Governor Gifford Pinchot, and others, from U. S. Navy Radio Station, NOF, Washington, to Evening Bulletin Building, Philadelphia, by courtesy of Robt. McLean, Jr., March 2, 1923.—Reproduced in the _Bulletin_, and in the _Washington Star_, March 3, 1923.

1923. Makes his first laboratory demonstration of Radio Vision (the instantaneous reproduction on a small picture screen of a distant performer or a distant scene), and of Radio Movies (the transmission of pictures from a theatre screen to a small screen in the home), June 14, 1923. See _Visitor’s Register_.

1924. Makes his first hundred-line photograph, June 15, 1924, portraits of true photographic values in which no lines appear. Photographs of President Calvin Coolidge, Dr. J. S. Montgomery, Chaplain of the House, William Jennings Bryan, etc. See letters of congratulations from subjects of these photographic tests.

1924. Sends message, in Japanese characters, from Charge d’Affairs, I. Yoshida, of the Japanese Embassy, Washington, i.e., sending from the old Navy Station, NOF, to Amrad Station, WGI, Medford Hillside, Massachusetts; reported and reproduced in _Boston Traveler_, December 4, 1924.

1924. Apparatus bought and used experimentally by U. S. Post Office Department, on night-flying section, Air Mail route, New York-San Francisco, first message night of December 3, 1924. See James W. Robinson’s telegram, December 15, 1924.

1925. Transmits Motion Pictures by Radio from standard motion picture film to be looked at directly on a small motion picture screen in the distant radio receiving set; Tuesday, March 31, 1925. S.L.A., F.M.A., J.N.O., J.W.R., T.P.D.

[Illustration:

This machine is the prototype of the motion picture projector in universal use the world over, the result of experimentation begun by Mr. Jenkins in 1890; the machine finished and publicly exhibited in 1893 and 1894. Later shown before the Franklin Institute, and thereafter in the U. S. National Museum. When it has completed its service in the Laboratory office, the Franklin Institute Museum will be the final depository. ]

[Illustration:

The accompanying cuts show the Elliott Cresson Gold Medal, awarded by the Franklin Institute, of Philadelphia, for a machine exhibited before the Institute in 1895 by Mr. C. Francis Jenkins. ]

[Illustration:

Later, in making a second award, that of the John Scott Medal, “in recognition of the value of this invention,” the Institute Committee said: “Eighteen years ago the applicant exhibited a commercial motion picture projecting machine which he termed the ‘Plantoscope.’ This was recognized by the Institute and subsequently proved to be the first successful form of projecting machine for the production of life-size motion pictures from a narrow strip of film containing successive phases of motion.” ]

[Illustration: ANNO DOMINI MDCCCCXXIV In recognition of services rendered to the screen by =C. Francis Jenkins——= as inventor of the motion picture projector—— =S=tory =W=orld =M=agazine of =H=ollywood, in a series of articles published in 1923–24 names =M=r. =J=enkins as one of— =T=he =T=en =G=reatest =F=igures in— =M=otion =P=ictures—=I=t now takes pleasure in making this formal acknowledgment of its judgment— =S=tory =W=orld——Jay Brien Chapman September _First_ _Editor_]

ANNO DOMINI MDCCCCXXIV

In recognition of services rendered to the screen by =C. Francis Jenkins——= as inventor of the motion picture projector——

=S=tory =W=orld =M=agazine of =H=ollywood, in a series of articles published in 1923–24 names =M=r. =J=enkins as one of— =T=he =T=en =G=reatest =F=igures in— =M=otion =P=ictures—=I=t now takes pleasure in making this formal acknowledgment of its judgment—

=S=tory =W=orld——Jay Brien Chapman September _First_ _Editor_

[Illustration: American Projection Society INCORPORATED ABILITY PROGRESS SCIENCE MEMBERSHIP CERTIFICATE This is to certify that C. F. Jenkins having proved his fitness has been duly received into The American Projection Society Inc. as a Honorary Member, and is entitled to all rights and privileges as such. In Witness thereof the Executive Officers of the Chapter have hereunto affixed their signatures. President Secretary Treasurer Date June 12, 1924]

American Projection Society

INCORPORATED

ABILITY PROGRESS SCIENCE

MEMBERSHIP CERTIFICATE

This is to certify that

C. F. Jenkins

having proved his fitness has been duly received into The American Projection Society Inc. as a Honorary Member, and is entitled to all rights and privileges as such.

In Witness thereof the Executive Officers of the Chapter have hereunto affixed their signatures.

President

Secretary

Treasurer

Date June 12, 1924

[Illustration: [Photographs]]

The Jenkins High Speed Camera

This camera was designed for the study of high speed motions; i.e., the flight of birds, recoil of guns, the impact of shell on plate, muscular activity of athletes, airplane behavior, mechanical motions, etc.

The normal rate of exposures is 1,000 to 3,000 pictures per second (4,000 pictures per second have been made).

It uses standard motion picture super-speed negative film. Prints from these negatives are made in any standard motion picture printer, and developed in the usual way.

The prints may then be projected in any standard motion picture projecting machine, giving an apparent reduction of 100 to 200 times in the speed of movement of the object photographed, and therefore easily studied.

The camera is fitted with 48 Zeiss Tessar lenses, F-3.5 and 2″ focus, and is driven by an automobile starting motor.

It weighs approximately 100 pounds, and therefore easily moved from place to place. (Weight of two 6-volt automobile batteries additional.)

Sunshine is adequate for illumination. If artificial illumination is employed, it should be equal to sunshine.

(NOTE: The explanation of the unusual speed possible with this camera lies in its lens system, for each lens may work as much as 150 per cent of the time; that is, the exposures overlap.)

[Illustration: [Photographs]]

The Genesis of Radio

_A Broadcast from WRC, November 20, 1924_

C. FRANCIS JENKINS

The history of radio is unique—at first only a scientific curiosity, and for years thereafter a boy’s plaything; when, all at once, without warning, the public takes it up with a suddenness no one foresaw, and for which no one was prepared.

An invention which behaves so peculiarly excites one’s curiosity to a study of its strange attraction; and of the beginnings of the scientific principles involved, now so knowingly discussed by mere youngsters.

Why, boys in the whole range of their ’teens discourse with fluency and understanding such mysteries as inductance, impedence and capacities; reactance, reluctance and rotors; harmonics, aerials, and mush; choppers, chokes and cheese; heterodyne, neutrodyne, and iodine; and we oldsters don’t know whether they are talking of medicine, music or food.

The only thing that saves us from everlasting embarrassment is that we have the gumption to keep our mouths shut.

So, determined to be ready for these “kids” the next time they come into my august presence, I start in to “bone up” on some of these funny words, and for a start I turn to a musty volume printed by Congress in 1879.

It appears that on January 16 of that year the business of Congress was stopped, and, in solemn procession, led by the Sergeant-at-Arms, the Chaplain, and the Vice-President, the Senate proceeded to the House chamber, where the Speaker handed his official gavel to the Vice-President, who said: “The Senators and Members of the Congress of The United States are here assembled to take part in services to be observed in memory of the late Joseph Henry.”

And, as I read the addresses made on that memorable occasion, and look up the references cited, I get the solution to my problem.

I find it was Joseph Henry who first discovered that breaking the circuit in a coiled wire “gives a more intense spark than the same wire uncoiled.” And so inductance was born, and later in his honor we name its unit of measure a “henry.”

Then he put iron inside the coil and got the first magnetic field; next he found that when he arranged a second similar coil near the first, the spark appeared in a gap of the second circuit, and so we have the first transformer.

He put parallel metal plates across the circuit, and he had a condenser; and finally he separated the circuits by many hundred feet, and the first radio signals were broadcast and picked up.

So we learn that to this modest but remarkable man we owe the simple coupling coil that the boys of the past twenty-five years have been using to telegraph to each other wirelessly.

And it is these American youngsters who have developed radio; who first set up two-way communication half-way around the world; who, through their Radio Relay League, kept Captain McMillan in touch with home during his long winter night in the Arctic ice; who kept the _Shenandoah_ in constant contact with headquarters in Washington during her recent transcontinental trip, official acknowledgment of which was publicly made by the Secretary of the Navy.

Radio eventually will touch our lives at more points directly and indirectly than any other discovery in the history of mankind, unless, perhaps, I should make an exception in favor of fire.

And the delightful thing about it all is that the inaccessible places are benefited the most by radio, those in the out-of-the way places are less lonesome, and the long day of the sick and shut-in is more endurable.

The farmer has his market reports on the minute, his weather forecasts in time for action, and he sets his clock by radio and gets his entertainment from the air.

Dispatched and guided by radio, the flying mail goes day and night with such clocklike regularity that its remarkable performance is no longer “news,” although industry has not yet waked up to the advantage and economy which can be effected by a larger use of the airmail.

Ships are guided into harbor through fog by wireless direction, and the captain was guided thereto by radio compass and radio beacon, and at sea summons aid in case of mishap or danger.

In commerce one may send letters, telegrams, bank drafts, or engineer’s drawings, as radio photographs of the originals, with photographic accuracy and autographic authenticity.

Men on the ground talk with men in a flying machine out of sight in the sky, an almost inconceivable fact.

This reason alone would warrant one in predicting that the defense of our country is definitely going to pass from the limited activities of the Army and Navy to an Air Department, for the plane has no boundary or limit of range in offense or defense.

And in addition there is the wireless direction of bomb-dropping airplanes, torpedo submarines, and floating mines, inanimate agencies obeying the distant, unseen hand.

And ultimately power will be transmitted to populous areas, over wireless channels, from the enormous unworked coal fields away up in the Arctic Circle.

The applications of radio are coming so fast in industry that it is hard to keep informed, but doubtless its most extended use will be in the home.

The use of microphone modulated radio to carry music and speech to our homes celebrated its fourth anniversary only two weeks ago.

And yet in this brief space (=1=) millions on millions have been entertained with the very best the artist has to offer; (=2=) a singer has been heard around the world; (=3=) and our President has addressed his fellow Americans as a single audience.

When onto the boundless range of audible radio is grafted the world-wide appeal of the picture, the ideal means of entertainment would seem to have been attained, for the picture is without language, literacy or age limitation.

By radio we shall see what is happening in a distant place; inaugural ceremonies, football, baseball or polo games; flower festival, mardi gras, or baby parade.

So when the development of radio as a service to the eye has progressed to a like extent with ear-service radio, we will bring the entire opera to your home in both acting and music, or even the Olympic games from across the sea.

It has been most satisfying to have had a part in the development of this wonderful medium of contact between individuals and between nations. My part being principally visual radio, I expect great things from Radio Vision.

And did you ever notice the curious fact that a great laboratory, despite its inestimable contributions to science and engineering, has never yet brought forth a great, revolutionary invention which has subsequently started a new industry, like the telegraph, telephone, and telescope; motion picture, typecasting and talking machines; typewriter, bicycle and locomotive; automobile, flying machine, and radio vision.

It has always been a poor man to first see these things, and as a rule the bigger the vision the poorer the man.

And, do you know, that is right comforting, too; for I sometimes think that perhaps I myself may yet do something worth while if I only stay poor enough, long enough.

Radio Patents of Interest

129,971 Loomis 235,469 Bell 571,463 Thompson 653,881 Pollack 660,199 Pollack 714,577 Gruhn 725,140 Roberts 841,387 DeForest 867,877 DeForest 879,532 DeForest 884,110 Stone-Cabot 929,930 Latour 934,969 DeForest 968,484 Kruh 980,356 Squire 980,357 Squire 980,358 Squire 980,359 Squire 1,015,881 Fessenden 1,030,240 Hoglund 1,059,763 Reisz 1,069,535 DeBernochi 1,097,871 Murphy 1,135,624 Rosing 1,141,850 Stille 1,161,734 Rosing 1,316,967 Moore 1,329,688 Voulgre 1,356,763 Hartley 1,370,504 Hammond 1,385,325 Jenkins 1,390,445 Jenkins 1,406,445 Culver 1,413,333 Jenkins 1,423,737 Sandell 1,434,064 Montielhet 1,436,676 Peterson 1,440,466 Jenkins 1,444,605 Heising 1,450,080 Hazeltine 1,454,532 Beatty 1,467,988 Hoxie 1,470,696 Nicholson 1,475,583 Hoxie 1,484,648 Jenkins 1,485,773 Espenshied 1,489,228 Hazeltine 1,505,158 Martin 1,521,188 Jenkins 1,521,189 Jenkins 1,521,190 Jenkins 1,521,191 Jenkins 1,521,192 Jenkins 1,521,205 Stephenson 1,522,305 Latour 1,525,548 Jenkins 1,525,549 Jenkins 1,525,550 Jenkins 1,525,551 Jenkins 1,525,552 Jenkins 1,525,553 Jenkins 1,530,463 Jenkins

[Illustration:

Note: As Washington is the birthplace of radio, and has been the birthplace of more revolutionary inventions, upon which great industries have been built, than any other ten-mile territory, it may be interesting, and appropriate, to add here a recount by Mr. Jenkins of Washington’s claims to intellectual stimulus.—EDITOR. ]

Washington, the City of Enchantment

_Broadcast from WCAP, September 26, 1924_

C. FRANCIS JENKINS

Washington is the home of our Federal Government; but it is more than that—it is a delightful place to work, a stimulus to excellence in mental activity. Those of us who had wandered about more or less aimlessly before we discovered Washington well understand how its genial climate called forth the Presidential praise of our honor guest from the cool, green hills of Vermont.

Add to the delight of the climate, the charm of Washington’s setting, and one appreciates why, from the Executive Mansion outward to the very rim of federal activity, all remain, if they can, after leaving office. Woodrow Wilson stayed here, until he passed away. President Harding was hurrying home when his end came. The only living ex-president resides in the District.

Abraham Lincoln was loath to leave Washington, it is said, and so preferred a summer cottage in the Soldier’s Home Grounds, as did many of his successors, rather than a more elaborate executive residence elsewhere, while the White House was getting its annual dressing.

In the house now occupied by the Cosmos Club, Dolly Madison ruled social Washington in such a scintillating setting that even the widows of presidents, with few exceptions, have made their later homes here.

Nor is it strange, for this is the city the unequaled plan of which was worked out with such loving care by Major Charles L’Enfant, as he leaned over a drawing board in his home near the old Tudor Mansion; the parks of the plan later beautified by the landscape gardener, Andrew J. Downing.

And this magnificent dream city had the proper antecedents, too, for it was from this very site the old Indian chief Powhatan ruled his own vast territory before ever the white man had set up the capital of a nation dedicated to peace and opportunity.