366 



Sd. The Longitvde, 



Reference must be made to the observations for the time at this 

 place as above given, and to those of June 28th, and June 30th, at 

 Chicago. They furnish the data for the times at each station, ap- 

 pHed to the following telegraphic signals exchanged between Chicago 

 and Waukegan, viz: 



Determination of the difference of Longitude heticeen Chicago and 

 Wavkegan, Illinois, by electric signals for comparison of time, 

 June 29th, 1653. 



Sidereal Chronometer No. 2557, fast of Waukegan sidereal time 

 (at ISA. 29m. sidereal time), Ih. Olin. 04s.28. 



Rate per sidereal day, -f 6.15s. or per sidereal hour, + 0s.2506. 

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

 ''time (at lih. 58m. mean time), 04m. 53s.42. 



Rate per mean solar day, -f 0s.30. or per mean solar hour, 0s.0125. 



1st. — Chicago sit^nals recorded at both stations. 



1st Mean. — Electric signals sent from Chicago to Waukegan, 111. 00 49.69 



2d. — \Vaukegan, Illinois, signals recorded at both stations. 



2d Mean.— Electric si-nals sent from Waukegan, 111. to Chicago, 00 49.69 

 1st Mean. — Electric signals sent from Chicago to Waukegan as 



above, 00 49.69 



Eemlt: — Waukegan Station, Illinois, west in longitude of Chicago 



observing station No. 2, by a mean of the two sets of signals, -j- 00 49.69 



