CELERITY OF DOUBLE-KEEDLE TELEGEAPH. 



consequently, their average length was 240 words. The total time 

 of transmission was 162 minutes, and, consequently, the average 

 number of words transmitted, per minute, was 16|. The greatest 

 speed of transmission was 201, and the least 8| words per minute. 

 As it might be considered probable that four or five years' general 

 experience and practice might have improved the ability of the 

 operators, I applied to the secretary of the Electric Telegraph Com- 

 pany, Mr. Foudrinier, requesting him to cause a sufficient number 

 of messages, transmitted in the ordinary course of business with 

 the double needle instrument, to be timed, which he was so obliging 

 as to do, in June, 1854, and the following were the results : 



11 Messages. Number of words in the addresses . .84 

 ,, ,, messages . . . 160 



Total number of words transmitted . 244 



Total time of transmission . . . .689 seconds. 

 Average number of words transmitted per minute . . 21 1 



It appears, therefore, that the average celerity of transmission 

 with this instrument has increased in the ratio of about 16 to 21. 



The greatest celerity of transmission was, in this case, 24|, and 

 the least 16| words per minute. 



229. The manner in which the magnetic electric current affects 

 the needle in the arrangement adopted by the Magnetic Telegraph 

 Company, being somewhat different from that produced in the com- 

 mon needle instruments, worked by the-Electric Telegraph.Company , 

 although the systems of telegraphic signals are not essentially dif- 

 ferent, it appeared to me to be not impossible that the difference 

 between the instruments might more or less affect the celerity of 

 transmission. I therefore requested Mr. Bright, the Secretary of 

 the Magnetic Company, to time a series of dispatches transmitted 

 in the ordinary course of business. This was accordingly done on 

 the 28th of June, 1854, and the following were the results : 



74 Messages. Total number of words .... 2792 

 Time of transmission . . . 102 m 8 s 



Average number of words per minute . . .27^ 



The greatest celerity of transmission attained in this series of 

 messages was 37|- words per minute. 



The entire series consisted of messages transmitted from London 

 to Liverpool, on a pair of double needle instruments, at different 

 times of the day, and were carefully tabulated. In the series, several 

 messages were included, the transmission of which was excep- 

 tionally slow, owing either to the difficult nature of the communi- 

 cations, consisting of long words in private cipher, or of the names 



63 



