The last paragraph had barely been written when news arrived of another form of telephone, surpassing Gray’s and La Cour’s in some respects as a conveyor of musical tones, but as yet unable to speak like Bell’s. It is the invention of Mr. Edison, an American electrician. He calls it the motograph. He discovered about six years ago the curious property on which the construction of the instrument depends. If a piece of paper moistened with certain chemical solutions is laid upon a metallic plate connected with the positive pole of a galvanic battery, and a platinum wire connected with the negative pole is dragged over the moistened paper, the wire slides over the paper like smooth iron over ice—the usual friction disappearing so long as the current is passing from the wire to the plate through the paper. At the receiving station of Mr. Edison’s motograph there is a resonating box, from one face of which extends a spring bearing a platinum point, which is pressed by the spring upon a tape of chemically prepared paper. This tape is steadily unwound, drawing by its friction the platinum point, and with it the face of the resonator, outwards. This slight strain on the face of the resonator continues so long as no current passes from the platinum point to the metallic drum over which the moistened tape is rolling. But so soon as a current passes, the friction immediately ceases, and the face of the resonator resumes its normal position. If then at the transmitting station there is a membrane or a very fine diaphragm (as in Reuss’s or Bell’s arrangement) which is set vibrating by a note of any given tone, the current, as in those arrangements, is transmitted and stopped at intervals corresponding to the tone, and the face of the resonating box is freed and pulled at the same intervals. Hence, it speaks the corresponding tone. The instrument appears to have the advantage over Gray’s in range. In telegraphic communication Gray’s telephone is limited to about one octave. Edison’s extends from the deepest bass notes to the highest notes of the human voice, which, when magnets are employed, are almost inaudible. But Edison’s motograph has yet to learn to speak.