242 DETERMINATION OF THE LONGITUDE OF SEVERAL 



point of North Cape, in the eastern extremity of Lake Erie. Subse- 

 quent observations by Captain Talcott have shown that North Cape is 

 in latitude 41° 44' 8", while the South Bend, so called, of Lake Mi- 

 chigan, is in 41° 37' 6", leaving a discrepancy of about eight geogra- 

 phical miles. In 1S17, deputy-surveyor Harris traced a boundary 

 line from North Cape, Lake Erie, S. 87° 42' W., towards South Bend, 

 Lake Michigan. This was recognised by the citizens of Ohio as their 

 true northern boundary, though diflfering from a parallel of latitude 

 required by the other condition of the charter. On the contrary, an- 

 other line fulfilling this condition of the charter was drawn by deputy- 

 surveyor Fulton, in 1818, being a continuation eastward of the parallel 

 of South Bend, Lake Michigan, to Lake Erie, seven miles south of the 

 stipulated point, North Cape, and cutting off from Ohio the mouth of 

 Maumee river, and the greater part of Maumee bay. This line was 

 claimed as their true southern boundary by the citizens of Michigan, 

 and hence the controversy referred, to, for the facts of which I am in- 

 debted to Mr Henry S. Tanner. 



To place this subject in its proper light before the interested parties, 

 Captain Talcott was sent to make the necessary observations. The 

 latitudes quoted above were obtained by a zenith micrometer, described 

 in Pearson's Astronomy. The results furnished by this instrument 

 present a remarkable uniformity. The probable error of a single ob- 

 servation does not exceed four hundred feet, and that of the mean for 

 each station, excluding the errors of the star-catalogues, less than two 

 hundred feet. It is hoped that these observations will be made public, 

 as they will serve to make known in this country, one of the simplest 

 and most accurate modes of determining latitudes by a portable instru- 

 ment. 



The labours of Captain Talcott were not confined to the determi- 

 nation of latitudes. At the two most important stations. South Bend, 

 Lake Michigan, and Turtle Island, Lake Erie, as well as at Huron in 

 Ohio, he observed a series of moon-culminations, the first, I believe, 

 communicated to this society. They form an important and valuable 

 contribution to the geography of Ohio, Indiana, Illinois and Michigan, 

 and will be highly useful in perfecting the maps of those states. In- 

 deed, these stations of Captain Talcott are the only well determined 



