Democratic Sentinel, Volume 3, Number 21, Rensselaer, Jasper County, 4 July 1879 — EDISON’S LATEST. [ARTICLE]

EDISON’S LATEST.

A Practical Test of His Loud-Speaking Telephone. [From the Philadelphia Times ] Edison’s latest invention, the electrochemical or loud-speaking telephone, was exhibited last evening for the first time in this country at the closing spring meeting of the Franklin Institute. Its operation had never been shown in public before except once, within the last few weeks, by Prof. Tyndall, at the Royal Institute, in London. A paper treating Upon the principle involved in the Construction of the instrument was read by Henry M. Bentley, President of the Philadelphia Local Telegraph Company, who then conducted experiments with the improved telephones. The instrument, he said, was simply an attachment of the electromotograph receiver to the Edison carbon transmitter. He Would use for this occasion the rude box which Mr. Edison had used in experimenting. If necessary, a coil to counteract induction could also be attached. Tile operation about to be exhibited, he said, would Uflt be so satisfactory as what would be Mown in the early future when an open and perfected instrument would take the place of the rude box which he had brought from Mr. Edison’s establishment on the previous evening. Mr. Bentley slipped a wheel of chalk upon an axle inside the little box, and, as the transmissions were received from the office of the telephone company, he continually turned a small crank projecting from the box. This caused the transmissions, which, under other circumstances, could not be heard at a distance of more than two or three feet from the receiver, to be audible in all parts of the hall. The speaking was as distinct as if the speaker were just at the other side of a board partition, with wide interstices between the boards, and the sound had all the characteristics of his voice. To show a comparison of Voices, Mr. Bentley several times called a different speaker to the transmitter. Whistling of such airs as “ Yankee Doodle,” “ Sweet By-and-By,” and “ Poor Little Buttercup” was particularly distinct and accurately transmitted. The sound heard by the audience, Mr. Bentley said, was two or three timeß as loud as that sent into the transmitter. The playing of a cornet came rather harshlj and irregularly at first, but, when Mr. Bentley had requested the performer not to hold the horn so close to the transmitter, the music was almost as satisfactory as if the player, instead of being nearly five squares away, were on the spot where Mr. Bentley stood. As in the case of the speaking, whistling, and other transmissions, it would seem that only a partition full of holes or wide cracks intervened between the performers and the listeners. Mr. Bentley saw no reason why people, in the near future, could not enjoy a lecture or concert going on at the Academy of Music by staying at home with their “electro-chemical” telephones. Being asked how far such performances could be satisfactorily transmitted, he replied that the question could not yet be definitely answered, but he believed that they could be heard at a distance of 100 miles as well as they were heard now. As a finale, a cornet performance of some of “ Pinafore’s ” liveliest airs came with astonishing distinctness and accuracy, sounding almost as well as if the performer was on the platform, and putting the audience in the best of humor.