306 HISTORY OF ASTRONOMY. 



viously adjusted by Mr. Saxton, so as to secure their 

 simultaneous striking on the transmission of the electric 

 current. The first trials which were made for the trans- 

 mission of signals were unsuccessful. The observers 

 were not provided with the means of holding communi- 

 cation by the ordinary mode of telegraphing, and if every 

 thing was not arranged exactly as had been previously 

 agreed upon, it was impossible to correspond for the pur- 

 pose of discovering the source of the difficulty. Com- 

 munication between Philadelphia and Washington was 

 however effected on the 10th and 22d of October, and 

 the difference of longitude approximately obtained. Sig- 

 nals for time by the clock were transmitted, and star 

 signals were exchanged. On the 10th of October, the 

 transit of the star 2838 Bailey over the seven wires of the 

 west transit instrument of the "Washington observatory 

 was signalized by Lieutenant Almy. The tune was noted 

 on the Washington clock by Lieutenant Almy, and also 

 by Mr. Walker, comparing together, by the ear, the seven 

 key beats with the clock beats. The same key beats 

 were also noted by Professor Kendall at Philadelphia. 

 These observations gave for the difference of longitude 

 between the two places 7 minutes and 34 seconds in 

 time. 



The experience of a few nights showed the necessity of 

 complete registering apparatus, such as is ordinarily em- 

 ployed by the telegraph companies ; and this was accord- 

 ingly ordered, but was not received in season for use 

 during the year 1846. 



