93 



2d. — Niles signals recorded at both stations. 



2d Mean. — Electric signals sent from Niles to Chicago, 

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

 above, __.---- 



05 28.367 



05 28.375 



Rest/It: — Niles Observing Station is east, in longitude, of 

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



sets of signals, - - - 



Longitude of Chicago station No. 3, 



- _ 05 28.37 

 + 5 50 31.20 



Longitude of Niles observing station west of the meri- 

 dian of Greenwich, - - - - 5 45 02.83 

 Equal, in arc, to ... 86^ 15' 42.45" 

 Latitude (approximate) of this station, as before given, 41° 49' 56" N. 



By a careful survey, conn(;cted with this determination, we derive 

 the positions of other points in Niles, as follows, viz. — 



The 4th or last point given in the above tabulation, is the station 

 where Captain Andrew Talcott observed in the \ear 1833. [t was 

 pointed out by Mr. William B. Beeson, who resided here at the time. 



