Friday 22d. Exercised on Horse back in the forenoon.
Called in my ride on the Baron de Polnitz, to see the operation of his (Winlaws) threshing Machine. The effect was—the Heads of the Wheat being seperated from the Straw, as much of the first was run through the Mill in 15 minutes as made half a bushel of clean Wheat. Allowing 8 working hours in the 24. this would yield 16 Bushels pr. day. Two boys are sufficient to turn the Wheel, feed the Mill, and remove the Threshed grain after it has passed through it. Two men were unable, by winnowing to clean the wheat as it passed through the Mill, but a common dutch fan with the usual attendance would be more than sufficient to do it. The grain passes through without bruising and is well seperated from the Chaff. Womn. or boys of 12 or 14 years of age are fully adequate to the management of the Mill or threshing Machine. Upon the whole it appears to be an easier, more expeditious and much cleaner way of getting out Grain than by the usual mode of threshing; and vastly to be preferred to treading, which is hurtful to horses, filthy to the Wheat, & not more expeditious, considering the numbers that are employed in the process from the time the bed is begun to be formed until the grain has passed finally thro’ the Fan.
Many, and respectable visitors to Mrs. Washington this Evening.
Friedrich, Baron von Poellnitz, occupied a farm of about 21 acres in the vicinity of Murray Hill on Manhattan, where he carried on a number of agricultural experiments. In 1790 he published an Essay on Agriculture, printed by Francis Childs and John Swaine. Later in the year he apparently sold his land to Capt. Robert Richard Randall and sometime before 1795 moved to Wraggtown, S.C. Poellnitz was an occasional correspondent of GW’s on agricultural matters (see Poellnitz to GW, 26 Dec. 1789, 20 Mar. 1790, 28 July 1795, and GW to Poellnitz, 29 Dec. 1789, 23 Mar. 1790, DLC:GW; , 123–24). In the late 1780s GW became greatly interested in Winlaw’s thresher after reading “A Description of William Winlaw’s Mill, for Separating the Grain from the Corn, in Place of Threshing,” written by Winlaw himself and printed in Arthur Young’s Annals of Agriculture, 6 (1786), 152–55. GW wrote Young, 1 Nov. 1787, that if the machine “possesses all the properties & advantages mentioned in the description, & you can, from your own knowledge, or such information as you can entirely rely on, recommend it as useful machine, where labourers are scarce, I should be much obliged to you to procure one for me . . . provided it is so simple in its construction as to be worked by ignorant persons without danger of being spoiled (for such only will manage it here) & the price of it, does not exceed £15” (PPRF). Upon investigation, however, Young found the accounts of the thresher “too vague to be satisfactory; I have too many doubts about it to put you to the expence of purchase and freight” (Young to GW, 1 July 1788, DLC:GW). GW had continued to direct inquiries to American owners of the thresher (see GW to John Beale Bordley, 17 Aug. 1788, MHi: Waterston Papers). The Winlaw thresher was undoubtedly the “new invented threshing machine conducted by Baron Pollnitz and other Gentlemen farmers, in farmers’ dresses, grinding and threshing grain” in the parade held in New York City in June 1788 to celebrate the ratification of the Constitution (, 52).