Page:Popular Science Monthly Volume 12.djvu/765

Rh form to its theoretic structure. The next, and by far the most brilliant step yet taken, was made by the American Franklin in demonstrating the identity of lightning and common electricity, and in the invention of the lightning rod. The Italians Galvani and Volta then followed, giving us the electrical batteries that bear their names; the Englishman Davy soon made an epoch in electro-chemistry; and Oersted, the Dane, came next with the discovery of electro-magnetism. This paved the way for the era of the successful establishment of the telegraph; and here our countryman Morse was a leader, whose name is everywhere indissolubly linked with the system.

All these achievements in the progress of the science were regarded with incredulous astonishment when they were made; but the recent exploits in the field of electrical invention and discovery surpass, if possible, in their wonderful results, all that has gone before, and here the work is exclusively American. The musical telephone of Elisha Gray, and the speaking telephone of Graham Bell, together with the Phonograph of Thomas Edison (which, although not an electrical machine, grew out of the telephone), were all invented in this country, and they nobly "crown the first two years of our new century." The import of these devices is being increasingly appreciated by scientific men as their powers are developed, and eminent foreign electricians have pronounced them the most extraordinary productions of the present century. Experimenters abroad may be expected to contribute to the elucidation of their conditions and principles, but they will do well not to overlook what has been accomplished here. Already, they are taking credit for contrivances which are but repetitions of American work. Dr. William F. Channing, of Providence, who, with other gentlemen of that city, have taken an active interest in the telephone from the outset, and contributed valuable aid to Prof. Bell in perfecting his invention, thus writes to the Journal of the Telegraph in reference to things done on the other side, that had been anticipated here:

"A considerable flourish has recently been made over the multiple telephone of M. Trouvé in Paris. As the speaking telephone is entirely an American discovery, it is worth while to keep the credit of what we do at home.

"The multiple telephone, that is, a cubical or polyhedral chamber, every side of which, except the front, is occupied by telephone-plates with magnets, etc., behind, was made last summer, by Henry W. Vaughan in Providence, before the speaking telephone had been seen in France.

"In a recent lecture upon the telephone before the Franklin Society of Providence, I had the pleasure of using a pair of sympathetic or rather responsive tuning-forks, made many months ago by Prof. E. W. Blake, of Brown University. These tuning forks were of the same musical pitch, and each mounted on a sounding-board. They were also tempered and magnetized, so as really to constitute permanent U magnets. Between the poles or ends of the prongs of each of these magnetic tuning-forks, a short soft-iron core, surrounded with a coil of fine insulated wire, was supported, very near, but not in contact with, the prongs of the tuning fork. These instruments were placed in a common telegraphic circuit a sixth of a mile apart. When the distant instrument was struck, the other responded so as to be heard throughout the lecture-room. This is a form of the responsive tuning-fork, much more beautiful than that figured in Nature, and ascribed to W. C. Röntgen; and it anticipated European application by several months."

have followed up the controversy that grew out of the publication of Dr. Carpenter's lectures on spiritualism, and, having printed in the an adverse review of that book by a leading representative of the spiritualist party in this country, we have republished in successive numbers of the  the replies to Dr. Carpenter