Boston Globe, January 19, 1919, page 39:
WIRELESS TELEPHONE WONDERFUL SCIENTIFIC DEVELOPMENTS BY AMERICANS DURING WAR
One of the wonderful developments in connection with the war was the perfection of the wireless telephone for use as a means of oral communication between airplanes in flight or with someone on the ground and miles away at the time. This invention, like the airplane itself, is wholly American--the fruit of the work conducted by a notable body of telephone engineers connected with the Bell System under John J. Carty and Col F. B. Jewett, chief engineer of the Western Electric Company.
This device is simply a development of the wireless telephone which astonished the world a few years ago when oral communication was made between Arlington, Va, and Paris and other distant points, and when at a notable dinner Pres T. N. Vail, of the Bell Company, spoke with Mr Carty who was thousands of miles away.
Among the first of the aviators to use this new airplane wireless was Lieut James C. Fair, commandant of cadets at Ebberts Field in Arkansas, although most of the experimental work was done at Langley Field, Va. Lieut Fair, before he entered the flying service, was Collection manager of the Metropolitan District of the New England Telephone & Telegraph Company, and he has resumed that position.
Sound of Voice in Ear
"The first thing that strikes you when you hear the sound of a voice in your ear while you are flying at a speed of 100 miles an hour and 6000 feet in the air is the uncanniness of the thing," said Lieut Fair to the writer. "There is something impersonal about the sound Of the voice, too, that impresses you as strange. What I mean is that you miss that intimate, personal quality in the voice that you get in the regular telephone.
"But that is not to be wondered at. The wonder is that the thing can be done at all, and done so simply. For you must bear in mind that the roar of the engine and propeller of a flying machine going 100 miles an hour is something awful. Yet the sound waves of the voice go through that roar and disturbance as if it didn't exist.
"To receive the voice all you have is a rubber helmet in which are the receivers, and this is connected with a switchboard beside you in the machine. The switchboard is connected by wires with a little generator in front of the machine under the center of the chassis and this in turn is connected with a few wire antennae that trail from the machine as it files. The power for the generator is derived from a little propeller turned rapidly by the rush of air as the machine flies.
"The transmitter is fastened to your chest in front so it is opposite the mouth all the time, and is connected with switchboard, generator and antennae as is the receiver. With this mechanism they talk to each other in the air when they are 10 miles apart or with someone on the ground, who may be even farther away.
"The man on the ground is equipped in the same way, except that he is connected with a regular generator in a shack somewhere near, and the antennae float away from the roof of the shack. I understand this wireless telephone we used on our flying machines on the Western front mystified the Germans a good deal. Yet we know the Germans had been working on a somewhat similar device, but had not been able to perfect it."
The history of the development of this airplane wireless telephone is rather interesting, for, besides the work done by the Bell engineers much credit is due Col Culver of the United States Army, who was one of the first to see the great advantage that would accrue from a machine by means of which orders could be sent by voice from the ground to fliers.
His intense interest in the subject and his experiments had much to do with the keen interest taken in the subject by the War Department. However, the basis of the whole thing was in the work done by Carty, Col Jewett and the other Bell engineers some years ago.
Baker Writes to Vail
The following letter, Dec 9, 1918, from Sec of War Newton D. Baker to Theodore N. Vail explains this: "My Dear Mr Vail--The chief signal officer, Gen Squier, has called to my attention the splendid spirit of cooperation and helpfulness which has been evinced during the war by the wonderful engineering organization of the American Telephone and Telegraph Company. The airplane radio telephone set, which has proven so satisfactory to the air service, and which has brought about entirely new methods of military use of airplanes, is a particular example of the result of this cooperation. The evolution and development of this and other important apparatus was made possible only because your engineering staff freely furnished the highly technical knowledge and skill necessary in the development, design and manufacture of the sets.
"Please express to your engineers my appreciation of the splendid service rendered."
To this Mr Vail replied as follows:
"Dear Mr Secretary--For all connected with the Bell System, by which the American Telephone and Telegraph, its associated operating and Western Electric companies are known, please accept our hearty appreciation of your commendatory words.
"Each corporation and individual, when called upon to serve in this work, responded without question and without hesitation and put forth their best efforts to aid.
"It will be great compensation to each and every one to feel that the efforts were not in vain, and it will gratify that personal element which each individual possesses to know that it was appreciated."
As a further appreciation of this work by the Bell engineers, Maj Gen George O. Squier, chief signal officer of the Army, wrote Col F. B. Jewett, chief engineer of the Western Electric Company, saying:
"I wish to call your attention to the letter of the 9th instant from the honorable, the Secretary of War, to Mr Vail, and in connection therewith I wish to add my deepest appreciation of the superb cooperation, the scientific knowledge, and the technical skill, all so freely and whole-heartedly given by that part of the Bell System which is the engineering department of the Western Electric Company, in the development of the highest technical signaling apparatus required for our expeditionary forces.
"Will you please see to it that the employes of your department who have striven so hard during the past 18 months to accomplish the phenomenal results attained are informed that they and their efforts are known and appreciated in Washington. Also permit me to extend to each and every individual concerned my best wishes for the future."
Supplied Navy With Outfit
More than a year before the United States entered the war the Bell people supplied the Navy with a wireless telephone outfit designed for communication between an airplane and a station on land, or on a ship. From this time on the manufacturing branch of the Bell System, known as the Western Electric Company, continued the work of perfecting light, compact sets which would be available for use on small vessels and on airplanes.
The first successful wireless test between an airplane and the ground was made with one of these sets which had been built prior to our entry into the war. The experiment was made on the Langley Flying Field in Virginia soon after we entered the war. This test was the result of a conference between Gen Squier, Col Jewett, C. C. Culver, Maj Reece of the British Army and Mr Craft, one of Col Jewett's assistants. At that conference Gen Squier was so impressed with what he saw that he ordered Col Jewett to equip airplanes with the Bell apparatus and to proceed with the development work.
From this time the work consisted in obtaining the smallest and lightest outfit, a convenient form of power plant to furnish the necessary energy, overcoming the noise made by the airplane itself, overcoming the inductive interference in the wireless telephone set arising from the airplane ignition system, designing the best telephone transmitter for the peculiar conditions on the airplanes and other questions of a similar nature.
So complete had been the fundamental work already accomplished and so rapidly was the work pushed, that on Dec 2, 1917, at the Wright Field, Dayton, O, an official demonstration was made between planes in the air and planes on the ground before the Aircraft Production Board and before officers of the Army and Navy.
Two planes were sent up into the air, each equipped with the Bell wireless telephone system. These systems were so arranged on the planes, which were two-seaters, that both pilot and observer received the messages, and the observer could communicate with the ground or with the other airplane, and the pilot and observer could talk to each other by wire telephone, this being an important point, as the noise in an airplane is such that pilots and observers cannot directly communicate with each other by spoken word. On the ground there was a wireless telephone outfit equipped with a land speaking receiver, so that all of the assembled officials could hear both the orders issued to the airplanes and the communications from the airplanes.
Planes Communicate by Phone
Orders were issued to each of the planes from the ground by wireless telephone and their receipt acknowledged from the planes by the same means, the orders issued being immediately executed. The planes also communicated with each other. In this test orders were Squier, Col Jewett, Col C. C. Culver, issued to planes from the ground over distances as great as 10 miles, a distance at which the planes were invisible from the telephone station. The planes communicated with each other over the same distance, at which distance, of course, each plane was entirely invisible from the other.
To appreciate what a tremendous advance was represented by this application of the Bell wireless telephone system, the best scheme actually employed at that time must be known. This did not provide any means of communicating between the planes. Wireless telegraphy was used to send from the planes to the ground and very occasionally from the ground to the plane. In addition to its limitations, this system required that the observer in the plane should be able to send by Morse code. The practical utility of this scheme was limited to reporting the results of artillery fire and correcting ranges, and to a limited extent for reporting from scout-planes.
The demonstration showed conclusively the success of the new system and made such a strong impression upon the officials present that immediately thereafter large orders were placed by both the Army and Navy, and the apparatus was also obtained by the Allies and used effectively in war work.