358 



Sth. 1858, Julij I2th. At Chicago Observing Station No. 2. 



Sidereal chronometer No. 2557, fast: 

 By 10 observations on u Lyrce, E. (at 



15A. S2m.) using horizon roof h. m. s. 



No. 1, - - - 1 01 30.12 



By 14 observations on u Bootis, W. 



(at 16/i. 12/77.) also using roof 



No. 1. - - - 1 01 30.41 



By E. and W. stars, using roof No. 1 



(at 15A. 52777.) - -f 1 01 30.26 A. m. s. 



f- 1 01 30.26 



By 5 observations on cc Lyroe, E., 



using horizon roof No. 2 (at ISA. 



45/77.) - - . 1 01 30. 



By 8 observations on u. Bootis, W., 



using roof No. 2 (at 15A. 57777.) 1 01 30.22 



By E. and W. stars (at 15/i. 51^.) 



using roof No. 2, . +1 01 30.11 



f- 1 01 30.11 



Result — Chronometer No. 2557, fast of sidereal time 

 for this station (at 15A. 51m. 305.) by 15 obser- 

 vations on « Lyrce, east, and 22 observations on 

 cc Bootis, west, - - - -f 1 01 30.18 



By comparison — Chronometer No. 141, slow of mean 



solar time for this station (at 8/t. 28/77. mean time) — 4 44.48 



9//t. 1858, July \bth. At Chicago Observing Station No* 3. 



Sidereal chronometer No. 2557, fast: 

 By 7 observations on ex, Corona^. Bo- 



realis, W. (at 19/i. O6/71.) using h. m. s. 



horizon roof No. 1, - - 1 01 40.54 



By 5 observations on a, Andromeda:, 



E. (at 20/7. I8777.) using also roof 



No. 1, - . -1 01 44.96 



