fnOej. 247 



Telegraph : 



semaphore, 68. 



loadstone, 88. 



Franklin's electric firing, 88. 



electrically dropped balls, 88. 



electric transmission of musical tones, 91. 

 of signals, 94. 



Morse register, 95. 



first line, 97. 



description, 98. 



reading by various senses, 100. 



Bain, chemical recorder, 101. 



Cooke needle, 108. 



Wheatstone needle, 108. 



House printing, 108, 110. 



Hughes printing, 108, 112. 



automatic systems, 109, 112. 



multiple transmission, 114. 



musical transmission, 120. 



musical receivers, 125. 



Way duplex. lii'J. 



from moving railway trains, 131. 



repeater. 150. 



short-line dials, 159. 



printing, 163. 



wireless. ( h. XXI, 170. 

 Telegraphic messages, receiving, 103. 

 Telephone, Chs. XV, XVI, 134, 145. 



author's first experiment, 91. 



experiments, 123. 



, at. l.T). 



speech receivers, 139. 

 . -' telephone. 141. 



lir'-t specification of, on record, 143. 

 how telephone talks, 145. 



' ( c,n~t met ion. 1 Hi. 



two methods of transmission: magneto an<l 

 fed resistance, 142, 149. 



