338 HISTORY OF ASTRONOMY. 



the transit clock at Cambridge, both before and after in- 

 terchanging signals, so as to ascertain their error and 

 rate ; and at both observatories, on each day of operations, 

 the meridian passages of a number of stars were observed, 

 in order to obtain the error and rate of the transit clocks. 

 The method of operation was as follows : The assistant 

 at Boston commenced at an even minute by his chro- 

 nometer, and sent second-beats for fifty consecutive 

 seconds. This was continued for ten successive minutes, 

 beginning always at the even minute, and the times were 

 noted by the transit clock at Fredericton. Sub- 

 sequently the observers at Fredericton took the initia- 

 tive and sent a series of signals to Boston. The following 

 are the results of these comparisons : 



1855, Jan. 23. Longitude by signals sent from B. to F. 17m. 57-38s. 

 Feb. 2. 



Feb. 10. 



Result of all the comparisons 17m. 5 7 -23s. 



During the winter of 1854-5, the telegraph operations 

 for longitude were extended as far as Macon, Ga., and 

 arrangements were made for continuing the work to 

 Montgomery and Mobile. In December, 1854, Dr. 

 Gould, assisted by Mr. Goodfellow, occupied the ob- 

 servatory at Columbia, S. C., and Mr. Dean took charge 



