369 



Determination of the difference of Longitude between Chicago and 

 Racine, Wisco?isin, by electric signals for comparisons of time, 

 September 6th, 1858. 



Sidereal Chronometer No. 2557, fast, of Racine, sidereal time, (at 

 22h. 2im. 4O5. siderial time,) Ih. 07m. 375.55. 



Rate per sidereal day, -f 65. ; or per sidereal hour, + Os.25. 



Mean Solar Chronometer No. 141, slow, of Chicago, mean solar 

 time, (at llh. 2lm. mean time.) 4m. 285.42. 



Rate per mean solar day, + 05.07 ; or per mean solar hour, -j- 

 005.03. 



1st. — Chicago sisinals recorded at both stations. 



1st Mean. — Electric signals sent from Chicago to Racine, 



00 36.804 



2d. — Racine signals recorded at both stations. 



2d Mean. — Electric signals sent from Racine to Chicago, 00 36.79 



1st Mean. — Electric signals sent from Chicago to Racine, as above, 00 36.804 



Result : — Racine observing station is west, in longitude of Chi- 

 cago observing Station No. 3, by a mean of the two sets of 

 signals, - - - - - - -f- 00 36.80 



VOL. VI. 



-3 E 



