Lot 485: ERICSSON, JOHN

485. JOHN ERICSSON (1803 - 1889) American engineer and designer of the Union's Monitor and the first screw-powered vessel. Fine technical content A.L.S., 2pp. 4to., Dec. 26, 1860, less than a year before he undertook the construction of the Monitor. In part: "...I warmed up the Primeros[?] engine last Monday just enough to drive some of the water out of brickwork and plaster and make a few turns sufficient to show that, when in motion, our clearances against cylinder heads are insufficient. A very tough matter to rectify, I can assure you. [I] ordered the main Rack Shaft out to change the length of Main Lever. In all such cases I have found that taking the bull by the horns to be the safest & best plan...we have more than a thousand joints separating these two very different pressures..." Very light dampstain in text, otherwise very good. Expertly inlaid. $500-700