Culpeper 25 March 1805
I am favourd with a present of intrinsic Value; the estimation of which is encreased by coming from a character who with Just propriety fills the first place in the Gift of Man! tho great that expression, I proudly boast transcendantly more. It is from Thomas Jefferson; a name, which will I believe duribly stand the test of Time; when that of Presidents Emperors and Kìngs are eventually obliterated. I wd thank you Sir if I had Language to express the feelings of my elated Heart.
Were I ever so much a proficient in the science of Apology, wd. not on this Occasion presume to exercise it; altho’ indeed there is before me, with respect to my Judgement or Opinion of a plough, a very fair opportunity, the more especially as the concentrated ingenuity and experience of the Wisest and best of Men have down to the present age been drawn to that important Subject; but rather, implicitly obey your command, by simply stating the little I know of the business, for which I am some indebted to observation & experience, but more to Necessity, the Legitimate Parent of invention; of my sort of Mould board herewith is a Model; as I may have Occasion to Mention both of Yours & also Mine; for distinction, I will call your broad toed Mould board A, the Narrow toe’d B, and that herewith C. A & B may be among if not the very best constructions of human Wisdom; but clearly enough are fitted for different purposes. A must be fixt on the plough so that its Toe shall immediately follow the Wing of the Share; the Coulter having Cut the turf perpendicularly and the Share horizontically, that Mould board then is of all others best calculated to take it up & turn it over with least resistance; the only objection to its construction, is, that it would make the Woodwork and Bar of the Share too long & too heavey for common use; but whether, in very Stiff Swardy Land, that inconvenience wd. not be fully compensated by the ease it would take up the Sod & turn it over, is with me matter of uncertainty, to be determined by fair experiments, at any rate there are two purposes in which it would most certainly excel; One of which is where the Farmer wishes to turn the Sod completely over, and give it (for the intended Crop) no other ploughing; the other is for pairing up handsom green turf for the purpose of sodding the bank of ditches, falls of Gardens &c. B. Will admit of a shorter lighter and more convenient plough, because its Narrow Toe is well calculated to come forward on the top of the Wing of the Share, and therefore the Woodwork may be shorter lighter and indeed Stronger; but as its shape begins to turn the Sod as soon as it is partially cut by the Share and must of course be forced forward while a part of the turf is yet uncut or immediately as cut; undoubtedly on that account meets with more resistance than A; but they both have on the top a curve given them, which if any way essential, is more than I can discover; if not, that curve must have a tendency in some degree to impede the Operation. If a plough is to enter and turn over the Surface of the earth on the principle of a Wedge, the smoother and straighter the sides of that Wedge, the easier it may be introduced and carried forward, in which respect it is that C differs chiefly from B, another is the Curving figure of the peice taken out of the tail part of C, which I conceive to add to its facillity, as well as laying the sod over neater and better; of this however I am not absolutely certain, as I never used One of another shape, but well aware that theory is so frequently at variance with practice, I will make the experiment. A & B are I presume calculated to be of Cast Iron, C of Wood; the Sort, (tho’ not altogether out of Choice). I always use, for which purpose I always select a tree that twists or winds naturally into the very Shape I wish it. In mentioning of the Wood work of a plough as above, shall be understood such as is best calculated for the Barshare, & Size for two Horses. Am an indifferent Slow hand to draw any thing, and not a moments time to Spare, will endeavour to discribe mathematically, such as I use, as if standing on a plane Vizt. the Beam from the Tenon that goes into the hande to the
|Middle||of the Mortice for the upright post||1 foot||10 In|
|thence||to the hole for the Screw brace||4 "|
|"||to fore part of the Coulter Mortice||7 "|
|"||to the Clvis pin hole||2||0 "|
|to the end being the length of the head||7 "||5 feet 4 In.|
to diverge, from the Coulter Mortice to the Clevis pin hole (to the right) at rate of an angle of 9 Degrees. Its Size will depend on the goodness of the timber which ought to have a Natural Cast, ought to Swell handsomely against the Mortices where Strength is wanting and largely again, & handsomely at the head where the Clevis is to be fixt. all the other parts putting off as small as will admit for proper Strength. the Handles 4 feet 2 In. long, bevelling from the hindend of the Beam at the rate of an Angle of 130 Deg. The Upright post 1 foot 4 In long, clear of both tenons starting forward at an Angle with the Beam that is taking the Angle behind the post at the underside of the beam, of 105 Degrees. The Barshare, its Bar, from the tailscrew to the fore part of the Mortice, 1 foot 2 Inches; thence to the point 1 foot 3 In; the Length of the Wing along the edge 1 foot 6 In: and diverging from the point of the Bar at the rate of 35 Degrees which will cause the broadest part at the hind end to be about 18½ Inches, when new; great care Should be taken that the Share be so framed on the Upright post and left handle that when the plough is in its proper posture on a plane that the distance of the head of the Beam (exactly against the Clevis pin hole) from that plane will Measure 14½ Inches, if for Midling Horses, if Very Large Horses, a Small Matter more not exceeding One Inch may be discretionally Allow’d; and the Lower end of the two Handles Should be so far firmly Seperated by proper pins as to cause the Lower end of the tale of the Mould board to be 9 Inches from the opposite side of the Bar, for that part should always be a tittle Narrower than the broadest end of the Wing of the Share or it will work very hard, and will throw the sod too far, for the Sod in falling over not only gains its own width but also gains its thickness. I am sorry I cannot well describe the head peice of this plough and its regulating Clevis, the Head should swell to the end 4½ Inches Wide, 7 In. from the end is the hole of the Clevis pin (as above) passing perpendicularly thro’ the Beam, within one Inch of the End is 3 other perpendicular holes tho’ smaller than the Clevis pin hole and at equal distance from each other on a Scribe made by putting one foot of the compasses in the center of the Clevis pin hole, the the other foot extending as above within one inch of the end of the head then Scribe a Circle in which at equal distance lay off the three smaller holes, to be bored as above, perpendicularly, then let the Clevis be made with holes at ends of its two Shanks to recieve the large pin thro’, then a cross plate being welded on it by the Smith and turnd in a circular manner so that 3 holes may be punched in it exactly corresponding with the 3 holes in the head of the Beam but the end of the Clevis moves perpendicularly round the end of the head which ought to be circular with 3 or 4 notches in it, in one of these notches the first Large Link unites the plough to the swingle tree to which the horses is fixt, so that the ploughman may cause his plough to go deeper or Shallower by moving that link higher or lower in those Notches—but the peculiar advantage of the thing is having it in his power to increase or decrease His furrow by Means of a small pin in any one of the holes at the point or end of the head. for if there be at that place 3 holes in the Clevis and 3 corresponding as above in the Beam that Enables him to make 9 alterations at pleasure, and for tending of Indian is a very great advantage; because, altho’ the Horse should walk on making the first furrow 12 Inches from the Corn the plough may be set by that Clevis to throw the Mould upon it, for the second furrow it may in a moment be alterd &c.
Another improvement is the regulating back band, which consists in the usual way of a broad strap of leather about 4 Inches Wide & something longer than those in common use, but without any Loop at the end extends down the Horses Side within the Chain that is between this side, On this strap near each end are sewd three narrower straps, suppose a little more than Inch wide each with Buckles to them and corresponding straps with holes in them a little higher up the back band to buckle to; two of these narrower straps go round the Chain the third one goes through a link of the Chain. they all three buckle up higher or lower at discretion of the ploughman, and has many advantages attending it.
of folly & its offspring Vanity, this poor tedious performance is guilty enough, of which however the humble performer is not so solicitious if this thing does not appear to border too much on the confines of Arrogance. It must not an answer or one moment of your invaluable time, but when I have the felicity of seeing you again at my poor Cot, I may have honor of an oppty of explaining, what I cannot so well do on paper. with all perfect and due regard Good & Worthy Sir I am Yr. most Obdt
DLC: Papers of Thomas Jefferson.