From his accounts we find that in 1759 he made thirty-four thousand one hundred sixty pounds of tobacco; the next year sixty-five thousand thirty-seven pounds; in 1763, eighty-nine thousand seventy-nine pounds, which appears to have been his banner tobacco crop. In 1765 the quantity fell to forty-one thousand seven hundred ninety-nine pounds; in 1771, to twenty-nine thousand nine hundred eighty-six pounds, and in 1773 to only about five thousand pounds. Thereafter his crop of the weed was negligible, though we still find occasional references to it even as late as 1794, when he states that he has twenty-five hogsheads in the warehouses of Alexandria, where he has held it for five or six years because of low prices. [Illustration: Looking across part of Dogue Run Farm to "Woodlawn," the Home of Nelly Custis Lewis] [Illustration: Gully on a Field of Union Farm, Showing Susceptibility to Erosion] He tried to raise a good quality and seems to have concentrated on what he calls the "sweet scented" variety, but for some reason, perhaps because his soil was not capable of producing the best, he obtained lower prices than did some of the other Virginia planters, and grumbled at his agents accordingly. He early realized the ruinous effects of tobacco on his land and sought to free himself from its clutches by turning to the production of wheat and flour for the West India market. Ultimately he was so prejudiced against the weed that in 1789 we find him in a contract with a tenant named Gray, to whom he leased a tract of land for ten pounds, stipulating that Gray should make no more tobacco than he needed for "chewing and smoaking in his own family." Late in life he decided that his land was not congenial to corn, in which he was undoubtedly right, for the average yield was only about fifteen bushels per acre. In the corn country farmers now often produce a hundred. He continued to raise corn only because it was essential for his negroes and hogs. In 1798 he contracted with William A. Washington to supply him with five hundred barrels annually to eke out his own crop. Even this quantity did not prove sufficient, for we find him next year trying to engage one hundred barrels more. Before this time his main concern had come to be to conserve his soil and he had turned his attention largely to grass and live stock. Of these matters more hereafter. CHAPTER V THE STUDENT OF AGRICULTURE