DESCRIPTION OF A MOULD-BOARD. NO. XXXVIII. The description of a Mould-board of the least resistence, and of the easiest and most certain construction, taken from a letter to Sir John Sinclair, President of the board of agriculture at London. [From the "Transactions of the American Philosophical Society, volume IV"]. by Jefferson, Thomas - [1799].

[Philadelphia: Printed and Sold by Thomas Dobson], [1799]., [1799].. Very good. - Quarto, 11-7/8 inches high by 9-1/8 inches wide. Unbound signatures from the "Transactions of the American Philosophical Society". 10 deckle-edged pages in all, with large uncut & untrimmed margins, consisting of pages 313 through 322. Lacking the engraved plate (a photocopy of which is here provided). Very good.

First edition.

Unbound sheets from volume 4 of the "Transactions of the American Philosophical Society".

Interested in improving farming methods and the tools and technology associated with agriculture, Thomas Jefferson observed the deficiencies of European plow designs while serving as minister to France. Jefferson was inspired to write out his plans for an improved moldboard in 1788. The moldboard (aka mould-board) is the wooden part of the plow that lifts up and turns over the sod which has been cut by the share and coulter. Mathematically inclined, Jefferson designed a more efficient board that allowed the plow to be pulled through the soil with the least force. He had a plow fitted with his new wooden moldboard in 1794 and, after 5 years of experimentation, Jefferson finally reported to Sir John Sinclair on the success of his design on March 23, 1798. His design had the additional benefit of being able to be "made by the coarsest workman". Although Jefferson went on to have his moldboard cast in iron in 1814, he never sought to patent it.