Swedish-American Army engineer (1803–1889) who designed and built the ironclad warship Monitor for the American Navy. ALS signed “J. Ericsson,” one page, 7.75 x 9.75, September 18, 1860. Letter to a gentleman. In part: “I find on calculation that a single 32 is hardly sufficient to drive the two pumps mentioned…in making the offer you will simply state that you propose to drive the two pumps at once and with great care.” Intersecting folds (one passing through a single letter of the signature), scattered soiling, and a few pencil notations to the top, otherwise fine condition. RR Auction COA.