Graham, J.[ames] D.[uncan] Autograph Letter Signed as Major, US Army Corps of Topographical Engineers. Washington, D.C. July 6, 1841. 2pp.+ docketed and postmarked address leaf (franked by Col. Abert, Corps commander) To Capt. W.G. William, Topographical Engineers, Buffalo, NY.
About British scientific instruments used in map-making.
“…about a year ago, Col. Abert requested me to make enquiries of Messrs.Troughton & Simms of London in reference to cost of a Zenith Instrument with double micrometer arrangement for minute differential measurements. This I suppose is the inst. you allude to…at the suggestion of Col. Abert, I do not propose to give any further orders on the subject. You will I presume hear from the Colonel… so that your own arrangement may be carried out in regard to a Repeating Circle…or such instrument as you would prefer.”
Senior to a young John C. Fremont in the Army’s Corps of Topographical Engineers, while Fremont was exploring and surveying the lands between the Mississippi and Missouri Rivers, Graham, more scientist than adventurer, had already trekked through the Rocky Mountains and Great Plains, surveyed the US-Canadian border, and, a year before writing this letter, had served as astronomer on the Army team that surveyed the border between the United States and the new Republic of Texas. Setting international borders was a complex scientific process, requiring the kind of advanced European-made instruments which Graham discusses in this letter to Captain Williams, who was then directing a survey the Northwestern Lakes.