Army engineer who designed and built the ironclad Monitor for the US government. ALS signed “J. Ericsson,” three pages on two adjoining sheets, 5 x 8, January 7, 1860. Letter to an associate concerning tests on a new engine. In part, “The engine at Meads was started last evening late, without our having a chance to look at any part of it after repair, fixing and setting lining. The young man who put it in motion says that he observed the supply piston lever to spring much, but instead of stopping the engine he kept the engine going until the old and now well ascertained cause of our trouble recurred.” He also adds a terse postscript, “Mr. Kitching’s agent in Alabama acts in a very shocking manner…Mr. Taylor it appears has brought home this intelligence from the South.” In fine condition, with light show through from text on reverse and mounting remnant to reverse of second page. R&R COA.