This idea was brilliantly demonstrated in practice in February, 1889, by Mr. W. J. Hammer, one of Edison's earliest and most capable associates, who carried on telephonographic communication between New York and an audience in Philadelphia. The record made in New York on the Edison phonograph was repeated into an Edison carbon transmitter, sent over one hundred and three miles of circuit, including six miles of underground cable; received by an Edison motograph; repeated by that on to a phonograph; transferred from the phonograph to an Edison carbon transmitter, and by that delivered to the Edison motograph receiver in the enthusiastic lecture-hall, where every one could hear each sound and syllable distinctly. In real practice this spectacular playing with sound vibrations, as if they were lacrosse balls to toss around between the goals, could be materially simplified.
The modern megaphone, now used universally in making announcements to large crowds, particularly at sporting events, is also due to this period as a perfection by Edison of many antecedent devices going back, perhaps, much further than the legendary funnels through which Alexander the Great is said to have sent commands to his outlying forces. The improved Edison megaphone for long-distance work comprised two horns of wood or metal about six feet long, tapering from a diameter of two feet six inches at the mouth to a small aperture provided with ear-tubes. These converging horns or funnels, with a large speaking-trumpet in between them, are mounted on a tripod, and the megaphone is complete. Conversation can be carried on with this megaphone at a distance of over two miles, as with a ship or the balloon. The modern megaphone now employs the receiver form thus introduced as its very effective transmitter, with which the old-fashioned speaking-trumpet cannot possibly compete; and the word "megaphone" is universally applied to the single, side-flaring horn.
A further step in this line brought Edison to the "aerophone," around which the Figaro weaved its fanciful description. In the construction of the aerophone the same kind of tympanum is used as in the phonograph, but the imitation of the human voice, or the transmission of sound, is effected by the quick opening and closing of valves placed within a steam-whistle or an organ-pipe. The vibrations of the diaphragm communicated to the valves cause them to operate in synchronism, so that the vibrations are thrown upon the escaping air or steam; and the result is an instrument with a capacity of magnifying the sounds two hundred times, and of hurling them to great distances intelligibly, like a huge fog-siren, but with immense clearness and penetration. All this study of sound transmission over long distances without wires led up to the consideration and invention of pioneer apparatus for wireless telegraphy—but that also is another chapter.
Yet one more ingenious device of this period must be noted—Edison's vocal engine, the patent application for which was executed in August, 1878, the patent being granted the following December. Reference to this by Edison himself has already been quoted. The "voice-engine," or "phonomotor," converts the vibrations of the voice or of music, acting on the diaphragm, into motion which is utilized to drive some secondary appliance, whether as a toy or for some useful purpose. Thus a man can actually talk a hole through a board.
Somewhat weary of all this work and excitement, and not having enjoyed any cessation from toil, or period of rest, for ten years, Edison jumped eagerly at the opportunity afforded him in the summer of 1878 of making a westward trip. Just thirty years later, on a similar trip over the same ground, he jotted down for this volume some of his reminiscences. The lure of 1878 was the opportunity to try the ability of his delicate tasimeter during the total eclipse of the sun, July 29. His admiring friend, Prof. George F. Barker, of the University of Pennsylvania, with whom he had now been on terms of intimacy for some years, suggested the holiday, and was himself a member of the excursion party that made its rendezvous at Rawlins, Wyoming Territory. Edison had tested his tasimeter, and was satisfied that it would measure down to the millionth part of a degree Fahrenheit. It was just ten years since he had left the West in poverty and obscurity, a penniless operator in search of a job; but now he was a great inventor and famous, a welcome addition to the band of astronomers and physicists assembled to observe the eclipse and the corona.
"There were astronomers from nearly every nation," says Mr. Edison. "We had a special car. The country at that time was rather new; game was in great abundance, and could be seen all day long from the car window, especially antelope. We arrived at Rawlins about 4 P.M. It had a small machine shop, and was the point where locomotives were changed for the next section. The hotel was a very small one, and by doubling up we were barely accommodated. My room-mate was Fox, the correspondent of the New York Herald. After we retired and were asleep a thundering knock on the door awakened us. Upon opening the door a tall, handsome man with flowing hair dressed in western style entered the room. His eyes were bloodshot, and he was somewhat inebriated. He introduced himself as 'Texas Jack'—Joe Chromondo—and said he wanted to see Edison, as he had read about me in the newspapers. Both Fox and I were rather scared, and didn't know what was to be the result of the interview. The landlord requested him not to make so much noise, and was thrown out into the hall. Jack explained that he had just come in with a party which had been hunting, and that he felt fine. He explained, also, that he was the boss pistol-shot of the West; that it was he who taught the celebrated Doctor Carver how to shoot. Then suddenly pointing to a weather-vane on the freight depot, he pulled out a Colt revolver and fired through the window, hitting the vane. The shot awakened all the people, and they rushed in to see who was killed. It was only after I told him I was tired and would see him in the morning that he left. Both Fox and I were so nervous we didn't sleep any that night.
"We were told in the morning that Jack was a pretty good fellow, and was not one of the 'bad men,' of whom they had a good supply. They had one in the jail, and Fox and I went over to see him. A few days before he had held up a Union Pacific train and robbed all the passengers. In the jail also was a half-breed horse-thief. We interviewed the bad man through bars as big as railroad rails. He looked like a 'bad man.' The rim of his ear all around came to a sharp edge and was serrated. His eyes were nearly white, and appeared as if made of glass and set in wrong, like the life-size figures of Indians in the Smithsonian Institution. His face was also extremely irregular. He wouldn't answer a single question. I learned afterward that he got seven years in prison, while the horse-thief was hanged. As horses ran wild, and there was no protection, it meant death to steal one."
This was one interlude among others. "The first thing the astronomers did was to determine with precision their exact locality upon the earth. A number of observations were made, and Watson, of Michigan University, with two others, worked all night computing, until they agreed. They said they were not in error more than one hundred feet, and that the station was twelve miles out of the position given on the maps. It seemed to take an immense amount of mathematics. I preserved one of the sheets, which looked like the time-table of a Chinese railroad. The instruments of the various parties were then set up in different parts of the little town, and got ready for the eclipse which was to occur in three or four days. Two days before the event we all got together, and obtaining an engine and car, went twelve miles farther west to visit the United States Government astronomers at a place called Separation, the apex of the Great Divide, where the waters run east to the Mississippi and west to the Pacific. Fox and I took our Winchester rifles with an idea of doing a little shooting. After calling on the Government people we started to interview the telegraph operator at this most lonely and desolate spot. After talking over old acquaintances I asked him if there was any game around. He said, 'Plenty of jack-rabbits.' These jack-rabbits are a very peculiar species. They have ears about six inches long and very slender legs, about three times as long as those of an ordinary rabbit, and travel at a great speed by a series of jumps, each about thirty feet long, as near as I could judge. The local people called them 'narrow-gauge mules.' Asking the operator the best direction, he pointed west, and noticing a rabbit in a clear space in the sage bushes, I said, 'There is one now.' I advanced cautiously to within one hundred feet and shot. The rabbit paid no attention. I then advanced to within ten feet and shot again—the rabbit was still immovable. On looking around, the whole crowd at the station were watching—and then I knew the rabbit was stuffed! However, we did shoot a number of live ones until Fox ran out of cartridges. On returning to the station I passed away the time shooting at cans set on a pile of tins. Finally the operator said to Fox: 'I have a fine Springfield musket, suppose you try it!' So Fox took the musket and fired. It knocked him nearly over. It seems that the musket had been run over by a handcar, which slightly bent the long barrel, but not sufficiently for an amateur like Fox to notice. After Fox had his shoulder treated with arnica at the Government hospital tent, we returned to Rawlins."
The eclipse was, however, the prime consideration, and Edison followed the example of his colleagues in making ready. The place which he secured for setting up his tasimeter was an enclosure hardly suitable for the purpose, and he describes the results as follows:
"I had my apparatus in a small yard enclosed by a board fence six feet high, at one end there was a house for hens. I noticed that they all went to roost just before totality. At the same time a slight wind arose, and at the moment of totality the atmosphere was filled with thistle-down and other light articles. I noticed one feather, whose weight was at least one hundred and fifty milligrams, rise perpendicularly to the top of the fence, where it floated away on the wind. My apparatus was entirely too sensitive, and I got no results." It was found that the heat from the corona of the sun was ten times the index capacity of the instrument; but this result did not leave the value of the device in doubt. The Scientific American remarked;