"The invention consists in a metallic collar vertically divided in two equal parts," Sewall Leach wrote, "one part of which is firmly secured to the deck, while the other half is arranged to be adjusted relative to the fixed half." A screw bolt allows the pressure of the collar on the rudder head to be regulated. Ordinarily, the top of a rudder would be a little loose where it entered the hull, resulting in "lateral motion of the rudder-head, and the consequent pounding and thumping in rough weather." With his adjustable collar, Sewall claimed, "the rudder is kept noiseless, and...much of the usual friction and wear is avoided, while the danger of the rudder being unshipped in heavy seas is greatly lessened if not entirely avoided."
The 1880 United States Census lists Sewall Leach of Penobscot, Maine, as a master mariner. His one son was also a sailor. The rights in this patent were assigned to Sewall himself and to Sabin Hutchings, a farmer, and J. D. Leach, presumed to be a relation.
Sewall Leach, Rudder-Collar, U.S. patent no. 100,419, Mar. 1, 1870.
1880 United States Census, NARA film no. T9-480, pp. 146B, 139C.