118 



h. m. s. 



Brought forward, — 02 53.56 



Add loncritude of Chicago station No. 3, - + 5 50 31.20 



3fZ Determination. 



Longitude of the centre of the public square of Michi- 

 gan City, - - - - - 5 47 37.64 



We have here three determinations of the longitude of this position: 

 one from observations in June, 1858, and two from observations in 

 1859, namely, April 28th and May 17th. The time-stars were much 

 better selected in 1859 than in 1858, which will appear on a compari- 

 son of their north declinations. Those in 1859, were all observed 

 near the prime vertical, but those of 1858 were observed before reach- 

 ing the prime vertical, east or west, and on different sides of it, though 

 at nearly equal altitudes. All things considered, we think the two 

 results of 1859 are each entitled to twice the weight of that of 1858. 

 On this principle the final result is presented, as follows, viz. — 



Summary. — Longitude of the Centre of this Public Square: 



h. m. s. 



By determination 1st, of June 21st, 1858, - 5 47 37.12 



By determination 2d, of April 28th, 1859, - 5 47 37.71 



By determination 3d, of May 17th, 1859, - - 5 47 37.64 



Result adopted, giving the 2d and dd determinations each a double 



weight. 



Longitude of the centre of the public square at Michi- 

 gan City, Indiana, west of the meridian of Green- 

 wich, - - - - . 5 47 37.56 



Equal, in arc, to ... 86° 64' 23".4 W. 



Latitude of the same point, as before given, 41° 43' 08". 33 N. 



From our survey, based on the above result, and observed azimuths 

 of Polaris for determining the true courses, we obtain the positions of 

 other points in Michigan City. The following table shows them all : 



VOL. VII. P 



