352 



meridian of Chicago, which I consider well determined with reference 

 to the meridian of Greenwich. 



I have already thus connected nine important points between Erie^ 

 Pennsylvania, and Prairie du Chien on the Mississippi river, and de- 

 termined approximately their latitudes; but I have not time, at this 

 moment, to add them here. I will, however, offer them at a future 

 time, and as soon as I can arrange them in a brief form. They go to 

 show that portions of the upper Mississippi river are laid down, even 

 on the latest and most approved maps, several miles out of place in 

 longitude. 



I wish to offer this paper, as it is, for :pubIication in the Society's 

 Proceedings, provided it be considered acceptable. 



J.D.GRAHAM, 

 Member of the Society. 



CONTRIBUTIONS TO GEOGRAPHY, No. 2. 



On the Latitude and Longitude of four additional positions on 

 Lake Michigan, and of Madison, the Capital of the State of 

 Wisconsin ; from astronomical ohservations by Lieut. Colonel 

 J. D. Graham, U. S. Corps of Topographical Engineers. 



Chicago, Illinois, December lith, 1858. 

 To the American Philosoplncal Societ}^, Philadelphia. 



In my letter of the 29th ultimo, I offered for the consideration of 

 the Society, and for publication in its Proceedings, some observations 

 on the latitude and longitude of Chicago. 



I beg leave now to offer, for the same, the following observations 

 in a brief form, made between the 20th of June and the 7th of Sep- 

 tember, 1858, for the determination of the geographical positions of the 

 following places. Calling Chicago I, as already presented, I will 

 enumerate the others, for convenient reference, as follows, viz: — 

 II. MICHIGAN CITY, INDIANA. 



III. WAUICEGAN, ILLINOIS. 



IV. RACINE, WISCONSIN. 



V. MILWAUKEE, WISCONSIN. 

 VI. MADISON, THE CAPITAL OF WISCONSIN. 

 The instruments used for ihe observations were all of a portable 

 character, adapted to ready use at night, whenever I had occasion to 

 halt in the course of a long journey by rail road. 



