ON SOME MARVELS IN TELEGRAPHY. 271 



the paper. At the receiving station of Mr. Edison's moto- 

 graph 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, out- 

 wards. 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 arrange- 

 ments, 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 communi- 

 cation 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 em- 

 ployed, are almost inaudible. But Edison's motograph has 

 yet to learn to speak. 



Other telegraphic marvels might well find a place here. 

 I might speak of the wonders of submarine telegraphy, 

 and of the marvellous delicacy of the arrangements by 

 which messages by the Atlantic Cable are read, and not 

 only read, but made to record themselves. I might dwell, 

 again, on the ingenious printing telegraph of Mr. Hughes, 

 which sets up its own types, inks them, and prints them, or 

 on the still more elaborate plan of the Chevalier Bonelli 

 "for converting the telegraph stations into so many type- 

 setting workshops." But space would altogether fail me 

 to deal properly with these and kindred marvels. There 

 is, however, one application of telegraphy, especially interest- 



