of Vocal and other Sounds by Wires. 117 



Distance about 50 yards. Conversation, singing, whistling, 

 breathing, and the sound of a light C tuning-fork (2^ inches 

 in fork) readily transmitted. 



Various similar arrangements were also made in house from 

 room to room, and finally carried to a distance outside, when 

 all the above effects, as also the transmission of whispering, 

 were clearly demonstrated, the persons at either end being 

 quite out of hearing in the ordinary manner. 



The communication was not limited to the persons at either 

 end of the wire ; additional connexions were occasionally made, 

 when three or more individuals could communicate with each 

 other. 



(3) Carried about 7 yards of No. 23 copper wire from one 

 room through an adjoining one to a room beyond, the wire in 

 its course passing below hvo doors shut above it, and for the 

 most part in contact with the carpet, but fastened at the ends 

 so as to produce some tension. Made two connexions of 

 No. 40 copper wire at angles with the main wire ; conversa- 

 tion was then readily carried on, and all the phenomena 

 already described produced. Subsequent experiments with 

 No. 16 copper wire arranged as above were found to yield 

 better results. 



A somewhat similar and equally suocassful experiment was 

 made by carrying the same size of wire down stairs, passing 

 below two doors and partly resting on carpet and wood. A 

 positive advantage is gained by resting the heavy wire in 

 this manner, the words being clearer and more distinct, and 

 free from the rumbling sound occurring with a suspended wire 

 free to move about. 



(4) Fastened No. 23 copper wire to telegraph-wire, made 

 another and similar attachment 75 yards further on, but within 

 two posts. Breathing, whistling, and tuning-fork sounds 

 readily transmitted. 



(5) Carried the latter attachment to 150 yards, thus ]?ass- 

 ing one post. Breathing, whistling, singing, and the sound of 

 the light C tuning-fork, formerly mentioned, readily trans- 

 mitted. No apparent loss though passing the support (the latter 

 was of the usual china-ware cup with binding-wire). The 

 speaking was not so distinct, although the different word- 

 sounds were discernible. This can be accounted for by the 

 fact that, as the poles were about 14 feet high, the attachment- 

 ends were free to swing about, which, combined with the ex- 

 posed situation of the main line, gave rise to a considerable 

 vibratory action due to other causes than the vocal sounds. 

 (See diagram, page 118.) 



(6) About 50 yards of No. 23 copper wire was laid out so 



