Making American Plow

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Jefferson was not only a farmer himself, but believed that farming was a blessed employment
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Jefferson's Virginia estate and the "laboratory" at which he tested many of his inventions
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Note the design of the moldboard on this Jefferson plow and its resemblance to the prow of a ship.

Even as common an object as the field plow has been romanticized as part of America’s westward expansion in the phrase ‘the plow that broke the plains.’ Yet the history of the plow in post-colonial America is a subject hardly touched upon except in diverse and scattered sources.

The McCormick hillside plow of 1831 and the Deere steel plow of 1837 are consequential in agricultural history because they represent the increasing momentum of westward expansion and the beginnings of maturing industrialism based primarily north of the Mason-Dixon Line.

Further, they represent the protection of design through patenting, which Thomas Jefferson had failed to do with his ‘mould board of least resistance,’ arguably the most consequential influence upon American agricultural efficiency of its time.

Jefferson asserted that ‘the plough is to the farmer what the wand is to the sorcerer’ and that the plow was ‘the most useful of the instruments known to man.’

Every agricultural advancement of the time was achieved through plowing, including erosion prevention and weed reduction. The efficiency of this work was dependent upon the wooden curvature on the furrow side that implemented the separation of the soil after the coulter tip had initially broken the ground. This wooden moldboard needed to be as efficient as the bow of a ship moving through water, and it was this objective that Jefferson ultimately achieved.

The British and the French received Jefferson’s moldboard with great adulation, with the British Board of Agriculture electing Jefferson to a foreign honorary membership in 1797 and the Parisian Society of Agriculture awarding a gold medal to him in 1807. The presentation of the moldboard to the American Philosophical Society in 1790 in Philadelphia hardly initiated the interest that this device should have created. To a great degree, this was because only the most affluent of farmers could afford to engage in the pursuit of new technology. Wealthy landowners imported British plows.

In the United States prior to 1620, plows were locally and individually made by a wheel right, carpenter or blacksmith based on their personal experiences, without a standard model as guide.

The moldboards were described as ‘often roughly plated over with pieces of old saw plate’ and were considered clumsy. Generally, they were referred to as ‘bull plows,’ ‘shovel plows’ or ‘bar-share plows,’ and it was the iron point rather than the moldboard that broke the soil while the moldboard itself failed to continue the movement of the soil past its form. Without an efficient moldboard, there was no continuing flow of soil movement beyond the initial pointed insertion. Thus shallow, 5-inch-deep plowing was the norm, and two men were needed to work the plow – one to steady and guide it and the other to press down on the beam at the front to insure penetration.

Yet for all this effort on the part of two men, many farmers at the time believed that shallow plowing was the preferred method and that bringing subsoil to the surface was harmful. Such common misconceptions did not encourage the average farmer to seek mechanical improvements in his plows, and to have plowed an acre was considered a good day’s work.

Up to three horses or six oxen were needed to counter the immense friction of poor designs. And here, too, the inefficiency of using multiple draft animals could be rationalized on the basis that oxen could always be fattened and sold for meat if they became lame from pulling. George Washington knew that the practices of an efficient plow could only be introduced by ‘gentlemen who had leisure and abilities to devise, and (the) wherewithal to hazard something.’ The common farmer had neither the time nor the capital to invest in improved technology and experimental agriculture.

Jefferson described himself as ‘the most ardent farmer in the state (of Virginia)’, owning ‘upwards of 10,000 acres of land, as well as horses, oxen, mules and Negro slaves.’ His agricultural experiments are recorded in his ‘Farm Book’ and, to John Jay he wrote, ‘Cultivators of the earth are our most valuable citizens … vigorous, independent and virtuous. He who might grow two ears of corn where only one could have grown previously (does) more essential service to this country than the whole race of politicians put together.’

The perfection of the plow ‘cannot be an idle speculation,’ he wrote, and the moldboard which raised, turned and inverted the furrow slice was the part upon which he concentrated.

In 1788, Jefferson traveled from Paris to Amsterdam and observed the plowmen in France, noting ‘the awkward figure’ of the moldboards. The experience led him to create geometrical diagrams of his plow, with instructions as to how to saw across and diagonally and to cut out pieces with the adze.

‘The offices of the mould board are to receive the sod after the share has cut under it, raise it gradually, and to reverse it. The fore-end of it, then, should be horizontal to the perpendicular. It should be as wide as the furrow, and of a length suited to the construction of the plough.’

Returning from France in May 1790, Jefferson promised his son-in-law Thomas Mann Randolph a model, knowing that his design was difficult to comprehend otherwise. Jefferson told Sir John Sinclair of the British Board of Agriculture in March 1798 that his was indeed the perfect moldboard, ‘advantageous in its form,’ ‘certain and invariable in the method of obtaining it with precisions.’ Having used it in Virginia for five years, Jefferson told Sinclair, ‘It answers in practice what it promises in theory.’ It offered the farmer ‘the least resistance possible’ in its movement.

Furthermore, besides its ‘invariable’ design offering minimal friction, ‘it may be made by the coarsest workman, by a process so exact that its form shall never be varied by a single hair’s breadth. One fault of all other mould-boards is that, being copied by the eye, no two will be alike.’

The two more useful classes of society, namely the laborer and the learned theorist, would benefit by his work.

Jefferson asserted that the moldboard should be ‘a continuation of the wing of the ploughshare, beginning at its hinder edge, and in the same plane’ and that the first office of the mold-board was ‘to receive the sod horizontally from the wing’ of the plowshare, ‘to raise it to a proper height for being turned over, and to make, in its progress, the least resistance possible, and consequently to require a minimum in the moving power.’

Beginning in 1793, Jefferson attached his moldboards to plows in lands he tilled in Albemarle and Bedford counties, Va., finding them to be of ‘practical utility.’ He incorporated a pointed toe over a square one as suggested by a Pennsylvania agriculturist, thus shortening the plow by six inches. The plow did not clog now in wet soil, but the square toe was steadier in running. Jefferson sent models of the sharp-toed version in 1806 to Strickland in England and to Pierre Samuel Dupoint de Nemours in Paris. Judge Harry Inns of Kentucky was told that the Jefferson moldboard with sharp toe provided 2 more inches of furrow depth than the usual type of moldboard. In 1810, Jefferson had informed U.S. President James Madison that the sharp-toed mold-board was now 9 inches shorter than the original. In fact, Jefferson sent models to mathematics professor Robert Patterson at the University of Pennsylvania, to political philosopher John Taylor Caroline of Virginia and to chancellor of New York state Robert Livingston.

Portrait painter Charles Willson Peale had his workers make a Jefferson plow and then introduced it to the farmers of Montgomery County, Pa. Peale urged Jefferson to lengthen the plow, and Jefferson agreed that he had yielded to the fashion in Virginia for light, short plows.

Nonetheless, Peale noted, ‘I have made the ploughman let go the handle and the plough has gone on for some steps as steadily and as even as a boat on the water.’

Jefferson also replaced wood with iron casting for the moldboard. Even up to 1813, many farmers believed that iron plows poisoned the soil, but in 1804, Philadelphian James House informed Jefferson that Henry Foxall of the Columbian Foundry in Washington, D.C., would cast the moldboard in iron if a thin pattern would be provided. In May 1812, Jefferson had 30 moldboards cast, and in May 1814, 24 more were cast, with the mold being retained for annual use. The ‘certain and invariable’ nature of Jefferson’s design was being confirmed with iron casting.

The moldboard of least resistance was practically efficient, but Jefferson wanted to have it tested with ‘one of these instruments used in England for measuring the force exerted in the drafts of different plows,’ namely the dynamometer.

Jefferson sought such a dynamometer in 1807 from James Monroe in London and in 1808 from David Baillie Warden in Paris. The Guillaume plow of France had been reported to move with the least resistance of any previous plow based on dynamometer tests, and on May 26, 1806, such a plow reached New York from Paris via England. The Guillaume plow was light and short and of wheel plow design, unlike, Jefferson noted to John Taylor, ‘the ploughs of Europe, barbarously heavy and long. I shall not now be afraid of sending to the (French) society one of our best ploughs … with my mouldboard to it.’

Ultimately, inventor Robert Fulton provided Jefferson with a dynamometer, and a competition was anticipated between the Jefferson plow, the Guillaume, a Parker double plow and two Peacock plows. It is doubtful the competiton occured, since Jefferson, a meticulous recorder of events, left no record of it.

But at this point, Jefferson was confident his was ‘the finest plough which has ever been constructed in America.’ Recognition was more pronounced abroad than at home, and Jefferson himself may not have encouraged the dissemination of the moldboard technology as well as he could have.

David Mangeim is a freelance writer and former history teacher who lives in Staten Island, N.Y. FC

Ambitious? Build it yourself!

‘Take a block (of wood), whose length, breadth and thickness are that of your intended mould board, suppose two and a half feet long and eight inches broad and thick. Draw the line a d and c d, Figure 1, with a saw, the toothed edge of which is straight, enter at a and cut on, guiding the hind part of the saw on the a b, and the fore part on the line a d, till the saw reaches the points c and d, then enter it at c and cut on, guiding it by the lines c b and c d till it reaches the points b and d. The quarter a b c d, will then be completely cut out, and the diagonal from d to b laid bare. The piece may now be represented as in Figure 2.

‘Then saw in transversely at every two inches till the saw reaches the line c e, and the diagonal b d, and cut the pieces with an adze. The upper surface will thus be formed. With a gauge opened to eight inches, and guided by the lines c e, scribe the upper edge of the board from d b, cut that edge perpendicular to the face of the board, and scribe it of the proper thickness, then form the underside by the upper, by cutting transversely with the saw and taking out the piece with an adze. As the upper edge of the wing of the share rises a little, the fore end of the board b c will rise as much from a strict horizontal position, and will throw the hind end e d exactly as much beyond the perpendicular so as to promote the reversing of the sod.’

For all its perfection, Jefferson’s moldboard was none the less modified by its maker, and in great detail:

‘Thus instead of first forming my block (of wood) as a b c d Figure 7, where a b is 12. I. and the angle of b a right one, I cut a wedge-like piece be off of the bottom, through the whole length of the block, b e being equal to the thickness of the bar of the share (suppose 1-1/2 I) because, the face of the wing declining from the top of the bar to the ground, were the block laid on the share without an equivalent bevel at its bottom, the side a b would decline from perpendicular, and a d from its horizontal position.’

Continuing in similar detail, he notes, ‘Those variations will be easy to any one after understanding the general principle.’

Thomas Jefferson and the ‘Mould Board of Least Resistance’

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