50 



2d. Observations for the Time. Augvst 8th, \ 858. 

 Sidereal chronometer No. 2557, fast: 

 By 9 observations on a Coronse Borealis, west (at m. s. 



I9h. 06m.) ..... 33 56.51 



By 8 observations on u, Andromedse, east (at 20/t. 



24m.) 33 57.29 



Result — Chronometer No. 2557, fast of sidereal time 



for this station (at 19/t. 45m.) - . + y3 56.90 



August 9th, 185S. Sidereal chronometer No. 2557, fast: 



1st Set. 

 By 13 observations on a Corona:; Bo- m. s. 



realis, west (at 19/i. 25m.) 34 02.58 



By 12 observations on cc Andromedse, 



east (at 20A. 03m.) - - 34 02.45 



1st Result — Chronometer No. 2557, 



fast (at 19h. 44?/z.) . - 34 02.51 m. 



H- 34 02.51 



'2d Set. 

 By 12 pairs of equal altitudes of cc Cygni, observed 

 east and west (at 20/i. S6m. 38.44s. or meridian 

 transit) - - - - . -f 34 02.73 



Result adopted — Chronometer No. 2557, last of si- 

 dereal time for this station (at 20/<. 10m.) H- 34 02 62 



?)d. The Longitude. 



In obtaining the difTerence of longitude between Erie and Chicago, 

 we use the time by sidereal chronometer No. 2557, for the meridian 

 of Erie as derived from the foregoing observations of August 9th. 

 The rate of that chronometer, carried forward from the period of the 

 determination of the said time to that of the signals, is derived from 

 the observations made at Erie on the nights of August 8th and 9th. 



The corresponding time for the meridian of Chicago, is derived 

 from the observations made there on the 4fh and 12th of August, 

 which give the rate of the mean solar chronometer No. 141, during 

 that interval, and also the means of reducing the Chicago time to the 

 period of the said signals. 



The signals and the results derived from them were as follows. 



viz. 



