Ill 



2d Michigan City signals recorded at both stations. 



2(1 Mean.— Electric signals sent from Michigan City to Chicago, 02 53.49 

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



as above, - - 02 53.49 



Result: — Centre of public square in Michigan City, east in 

 longitude, of Chicago observing Station No. 3, by a mean 

 of the two sets of signals, _ _ _ 



Longitude of Chicago Station No. 3, 



Determination 2d. 



Longitude of the centre of PubHc Square at Michigan 

 City, 



— 02 53.49 

 + 5 50 31.20 



5 47 37.71 



I was obliged, on the 17th of May, 1859, to go again to Michigan 

 City, on public duty, and this visit enabled me to obtain a third result 

 for the longitude of this place, as follows, viz. — 



1859, May, 27th. At the same Station. 

 Sidereal chronometer No. 2557, fast : 

 By 13 observations on /3 Geminorum, h. m. s. 



west (at 11 A. 43m.) - - 1 33 29.30 



By 9 observations on e Leonis, also 



west (at I3h. 01m.) - - 1 33 29.23 



By 22 observations on 2 West Stars, 

 (at I2h. 22m.) 



1 33 29.26 h. m. s. 

 }- 1 33 29.26 



By 13 observations on a. Coronse Borealis, east (at 

 I2h. 02m.) .... 



+ 1 33 29.30 



Result — Chronometer No. 2557, fast of sidereal time 



for this station (at I2h. 12m.) - + 1 33 29.28 



