Detroit, October 3, 1820.
Sir: On the eve of separating from my associates in our late tour, I owe it to them and to myself, that I should state to you my opinion respecting Captain Douglass and Mr. Schoolcraft.
I have found them, upon every occasion, zealous in promoting the objects of the Expedition, indefatigable in their inquiries and observations, and never withholding their personal exertions. Ardent in their pursuit after knowledge, with great attainments in the departments of literature to which they have respectively devoted themselves, and with powers which will enable them to explore the whole field of science, I look forward with confidence to the day when they will assume distinguished stations among our scientific men, and powerfully aid in establishing the literary fame of their country.
Should any object of a similar character again require similar talents, I earnestly recommend their employment. Whoever has the pleasure of being associated with them, will find how easily profound acquirements may be united with that urbanity of manners, and those qualities of the heart, which attach to each other those who have participated in the fatigues of a long and interesting tour.
Very respectfully, sir,
I have the honor to be
Your obedient servant,
LEWIS CASS.
Hon. John C. Calhoun, Secretary of War.
2. TOPOGRAPHY AND ASTRONOMY.
Topographical materials were collected by Capt. Douglass, U.S.A., for a map of the northwestern portions of the United States, embracing the complete circumnavigation of the great lake basins, and accurate delineations of the sources of the Mississippi, as low down as the influx of the River Wisconsin. Being provided with instruments from the Military Academy of West Point, astronomical observations were made at every practical point over the vast panorama traversed by the Expedition. A line of some four thousand miles of previously unexplored country was visited; his notes and memoranda for a topographical memoir were full and exact; and they were left, I am informed, in a state of nearly perfect elaboration, accompanied by illustrations, and many drawings of scenery. Having written to his family recently, for the astronomical observations, they were transmitted by his son in a letter, of which the following is an extract:—
Geneva, June 23, 1854.
Dear Sir: I inclose you herewith, on another page, the results of my father's observations of latitude and longitude, so far as I have been able to collect them. His calculations indicate great pains and labor to obtain accurate results. They are too voluminous to copy. I trust, however, that I have been as particular as was necessary in the inclosed memoranda. If anything else is wanting, I should like you to inform me.