American inventor (1742 - 1824) during the Revolutionary War. He is credited with creating the first submarine ever used in combat, while studying at Yale University in 1775. He called it the Turtle because of its look in the water. His idea of using water as ballast for submerging and raising his submarine is still in use today, as is the screw propeller, which was first used in the Turtle. Manuscript DS, completely written and signed by Bushnell, one page, 9 x 4, February 15, 1783. Signing as a witness for a document allowing the bearer to collect payment owed, in part: “Signed in my presence, D. Bushnell, Capt. Tappen and Mssrs.” In fine condition, with intersecting folds, scattered light toning and creasing, and light show-through from ink on reverse. RRAuction COA.