25 



CONTRIBUTIONS TO GEOGRAPHY, No. 3. 

 On the Latitude and Longitvde of eighteen additional positions in 

 the ?^'orth and Northwest of the United Slates. Also a review 

 of two positions (II. and VI.) previously reported. From astro- 

 nomical observations, bi/ Lieut. Colonel J. D. Graham, U. S. 

 Corps of Topographical Engineers. 



Clncago, Illinois, June, 1859. 

 To the American Philosopliical Society, Philadelphia. 



I wish now to offer a third contribution to the geography of the 

 United States, for publication in the Proceedings of the Society, if 

 deemed acceptable. 



I will indicate the positions by a continuation from the numbers 

 used in the preceding contribution, (No. 2,) published at jip. 852 to 

 388, of Vol. VI. of the Proceedings. They are as follows, viz: — 

 VII. ASHTABULA, OHIO. 

 VIII. ERIE, PENNSYLVANIA. 

 IX. TOLEDO, OHIO. 

 X. PRAIRIE DU CHIEN, WISCONSIN. 

 XI. DUNLEITH, ILLINOIS. 

 XII. DUBUQUE, IOWA. 



XIII. FULTON, ILLINOIS. 



XIV. LYONS, IOWA. 



XV. ALBANY, ILLINOIS. 

 XVI. CAMANCHE, IOWA. 

 XVII. CITY OF ROCK ISLAND, ILLINOIS. 

 XVIII. FORT ARMSTRONG, ILLINOIS. 

 XIX. DAVENPORT, IOWA. 

 XX. NEW BUFFALO, MICHIGAN. 

 XXI. NILES, MICHIGAN. 

 XXII. ELYRIA, OHIO. 

 XXtll. CLEVELAND, OHIO. 

 XXIV. COLUMBUS, OHIO. 

 I wish, also, to offer a review, for the purpose of verification, of the 

 following positions previously reported, viz: — 



II. MICHIGAN CITY, INDIANA. 

 VI. MADISON, THE CAPITAL OF WISCONSIN. 

 The instruments used in making the observations were the same as 

 previously used, and described in page 35.3 of Vol. VI. of the Society's 

 Proceedings. The system of observation was also the same as was 

 described in the previous papers published in that volume. 



VOL. VII. D 



