44 THE SCIENTIFIC PAPERS OF 



Mr. Varley mentioned that his attention had been accidentally 

 directed to the possibility of constructing a telegraph, the signals 

 of which would be communicated by the sense of touch. He had 

 himself been able, by touching the wire whilst an instrument was 

 at work, to interpret the signals by feeling ; and he thought 

 possibly this idea might ultimately be practically worked out. 

 Mr. Varley also gave a description of an instrument exhibited by 

 him termed the acoustic telegraph. He begged to ask Mr. 

 Siemens at what rate the Malta cable was worked ? 



Mr. Siemens replied he believed at the rate of about 12 words 

 per minute, though that very much depended on the skill of the 

 operator. 



Mr. Varley added that the experiments with the Atlantic cable 

 had led certain electricians to the conclusion that a small wire 

 conducted more rapidly than a large wire, a conclusion with which 

 he (Mr. Varley) did not agree. If it should be established that 

 the larger wire was the best conductor, he did not apprehend that 

 the expense of a submarine cable would be materially increased by 

 its adoption. The cost of the present Atlantic cable was about 

 100 per mile, of which sum 60 was due to the outer iron 

 sheathing, and 40 to the copper wire and gutta-percha covering, 

 and of this he thought the gutta-percha cost the larger portion. 



Mr. S'iemens said, in reply to Mr. Smith, that whatever his or 

 Mr. Brett's merits might be in having first suggested the long 

 spiral iron sheathing of electric cables, there could be no doubt 

 about the fact, as stated in his (Mr. Siemens's) paper, that it was 

 actually constructed according to the process patented by Messrs. 

 Xewall & Co. for twisting wire ropes. He felt surprised at Mr. 

 Latimer Clark's assertion, that Oersted, Schweigger, and Ampere, 

 were not the originators of the science of electro-magnetism. The 

 electric charge in undergound line-wire was first observed by his 

 brother, Werner Siemens, and fully described in a memoir, pre- 

 sented to the French Academy in 1849, whereas underground 

 line-wire had not been introduced into this country till 1854. He 

 was glad Mr. Clark acknowledged the superiority of the recording 

 over the needle instrument, but did not feel surprised at his de- 

 fending the latter, very much on the principle upon which one 

 would defend an absent and dying friend. Mr. Highton had also 

 defended the needle instrument, on account of its comparative 



