New York Times, April 27, 1902, page 1:
GOVERNMENT TEST OF WIRELESS TELEGRAPHY
Extraordinary Results of a System Said to be New.
Experts Observe Invention of Prof. R. A. Fessenden of the Weather Bureau by Which 127-Word Message Is Sent Fifty Miles.
Special to The New York Times.
WIERS POINT, Roanoke Island, N. C., April 20.--While the newspapers have been resounding with accounts of the invention of various wireless telegraph systems, all of which fall short of complete practicality in some respect, the United States Government has been quietly at work for the past two years in perfecting a system of its own which it believes has overcome all the obstacles and remedied all the defects of the other systems.
The system is now essentially complete, and yesterday it was tested before experts of the Navy Department, who had no hesitation in pronouncing it superior to all other systems, and who will recommend it to the department for adoption. Earlier in the week Gen. Greely, Chief of the Army Signal Service, had witnessed its operation, and it is understood that he takes the same view of it.
The system is to be known as the Fessenden system. It is the invention of Prof. R. A. Fessenden of the Weather Bureau, and it is Prof. Fessenden, who, under the direction of Chief Willis L. Moore of the Weather Bureau, has for the past two years isolated himself from the world in this remote corner of the seacoast to conduct the experiments which are now reaching a conclusion.
Unless the Weather Bureau is greatly mistaken the possibilities of the Fessenden system are tremendous, and the naval experts who have witnessed to-day tests, and who have made a study of these questions, do not seem to think that the Weather Bureau's claims are too high. The system has been practically completed for some little time, and messages have been flashing back and forth between Wier's Point and Hatteras Inlet several times a day for two weeks
Gen. Greely was here on Wednesday; he was, it is said, delighted with what he saw, and it is understood that the Fessenden system will be tried in Alaska, where the signal service is anxious to use the best system of wireless telegraphy.
The real test, however, was made yesterday under orders from Rear Admiral Royal B. Bradford, chief of the Bureau of Naval Equipment. Two naval officers came down here to witness it. They were Lieuts. A. M. Beecher and J. M. Hudgins, both of whom have studied the various systems of wireless telegraphy. Dr. O. H. Tittmann, Superintendent of the United States Coast and Geodetic Survey, and his assistant, Dallas B. Wainwright, a brother of Commander Richard Wainwright, came with them.
Prof. Fessenden was found at Manteo, from where the party proceeded to the station at Wiers Point yesterday. His assistant at Hatteras Inlet, fifty miles away, had been instructed to make a test which should comprise not only signals, but complete messages. The operator at Hatteras was to telegraph hourly. There is no receiving instrument at Hatteras Inlet, although one will be put in before the test is completed. The next test will comprise both the sending and receiving of messages at Wiers Point, although yesterday's test was limited to receiving. The Hatteras operator was to begin slowly, sending only from three to ten words a minute for the first ten minutes, and after that to increase his speed until he was sending as fast as he could. But, as luck would have it, something turned up which made the test more complete than Prof. Fessenden had counted upon. It happened that at the last moment, too late to reach Prof. Fessenden by wire, Chief Moore found urgent need to reach Prof. Fessenden with a message. There is no telegraph wire on Roanoke Island; the nearest station is at Nags Head, and that is closed. Chief Moore therefore determined to try the chance of catching the inventor with his own system, and accordingly he wired his message to Fessenden's man at Hatteras, directing him to repeat it by wireless to Roanoke Island. The message was promptly forwarded and received without a mistake. It was 127 words in length, the longest message yet received by the Fessenden system.
NEW RECEIVING PROCESS.
It should be explained that the principal feature of Prof. Fessenden's invention, that which differentiates it from the other systems, is in the receiving process. Heretofore it has been believed that messages by wireless telegraphy, no matter what the system, could not be received without a coherer. Prof. Fessenden conceived the idea that a receiving instrument could be constructed vastly more sensitive than the coherer, and that if this could be done every obstacle in the way of making wireless telegraphy completely practical for business purposes would be removed. This instrument, the successor of the coherer, he calls the "wave detector."
The test went along hour by hour yesterday without a hitch. Late in the afternoon one of the messages failed to come through in its entirety owing to the interference of lightning between Wiers Point and Hatteras. The system has a lightning arrester, but the one Prof. Fessenden had had been burned out, and it was therefore impossible to avert this accident. With this exception there was no flaw in the test.
While the Naval officers and the officers of the Coast and Geodetic Survey declined to give a full expression of their views in advance of their official reports, the following statement is of interest as showing their attitude:
"We realize that the Professor's work has been accomplished. The details had not been completely worked out, but then was enough to impress us. The possibilities are greater than those of any other system. The most extraordinary thing about it was that Professor Fessenden employed so little power to get his results. He employed only a quarter of an inch spark and got reliable messages over a distance of fifty miles. No coherer would do that short of a two inch spark, employing much greater power. Then it is more positive than the Marconi system in taking code messages."
The following statement was made by Professor Fessenden to THE NEW YORK TIMES correspondent at the conclusion of the test:
"This work was taken up about two years ago, at the instance of Prof. Moore of the Weather Bureau, who saw the advantage which a practical system of wireless telegraphy would have for use in distributing Weather Bureau signals and in obtaining data for making forecasts. At present they can only obtain meteorological data from the land, and predictions based on these are frequently vitiated by the condition of affairs on the Atlantic. It was believed by Prof. Moore that if we had means whereby the state of the barometer, &c., out on the ocean could be sent in, both on the Atlantic and Pacific Oceans, much more accurate forecasts could be made.
"I was asked to undertake this work, and we went down to a point on the Potomac River and started work. The first point that was taken up was the nature of the phenomena involved. We found that it was not due to Hertzian waves, but due to a new form of waves that had never before been investigated, a wave that did not travel outward in a straight line through space, but followed the surface of the conductor. We followed these waves up over hills and along level places and across land, and produced interference with them until finally the behavior of this class of waves had been traced out with absolute certainty under every condition. We next traced the depth which these waves penetrated the surface of the earth or water, and found that the maximum penetration was about one foot for sea water or three feet for land.
"We next took up the question of measurement of energy radiated out by different forms of apparatus and measurement at the amount of energy required to work various forms of receivers.
"We next measured the losses in transmission and determined these, and were finally able to calculate about how much energy we would get at the receiving station with considerably more accuracy than a telegraph designer can tell how much energy he will have available at the end of his line. On actual tests our calculations were then checked up and found to be accurate for all distances between thirty yards and seventy-five miles
"Having found the laws and perfected the generating apparatus, we next turned our attention to the receiver. We systematically took up the various properties of matter, such a light, heat. friction, &c., and worked out the best form of receivers which we could devise in each class. Of these we have selected three or four, and one of these is the one which was used in the tests before the signal service and the representatives of the Navy Department. This is by no means the most sensitive of our receivers, but it works well with about one-five hundredth of the energy required by the coherer, and it seemed to be the form which could be most rapidly developed.
The work is by no means finished. We have also paid attention to selective methods and multiplexing methods. We have four or five methods, all of which have been successfully tested in practice, and do not anticipate any trouble in this direction. But there is a good deal more of detail work to be done before we will be through with the subject, the designing of the best form of switches, keys, automatic devices to prevent accidents to the apparatus, the best form of tuning devices, &c., but these are merely matters of experiment and will be finished just as soon as we can cover the grounds.
WIRELESS TELEPHONY ASSURED.
"As regards wireless telephony, it can be stated definitely that telephoning up to at least 200 miles is absolutely certain of accomplishment. We do not, however, intend taking up this work until we have finished our work on the wireless telegraph, but we can definitely state that it is certain of accomplishment.
"The essential difference between my system and Marconi's is difficult to describe, because in no point are the two systems alike. Marconi uses an air transformer at the sending end and concentric cylinders and has his capacity arranged in a certain way. I use neither of the above, and my capacity is arranged in an entirely different way. At the receiving end Marconi uses an imperfect contact, that is a coherer. I use no imperfect contact, every contact used in my receiving apparatus being of solid metal, and there is no principle similar to that of the coherer involved, the method depending upon an entirely different physical law. Naturally therefore, all the details of the receiving apparatus are entirely different."