From Nathaniel Ellicott
Occoquan 28 March 1811
My Freind Tho Jefferson Esq
I have before me your letter of Enquiry of 24th. As you seem to wish your Manufactory of Plaster upon a small scale I am Verry Inclined to think, that the new mode of breaking it by a Cast Iron screw firmly fixed Immedeately over the Mill hopper is much more simple, and much cheaper, but if you wish (tho you say not) to go upon a large scale, I have always been of opinion that hard Knocks is best suited to breaking any Kind of stone Expeditiously. But if you beat with pestles your stones cannot Run while you beat with the same shaft, it Creates too much Jarring, upon Every consideration I would Recommend the screw upon your scale, and Altho I have often seen them at work, I am not at the moment able to describe the fixtures to your satisfaction
Oliver Evans of Philadelphia Casts and sells those screws,1 and will ship you one to Richmond with Directions to fix it up at your Request If I did not fully believe this mode would suit better than the one I pursue, I would with pleasure give you a Minute discription of the pestle Plan, and if you should determine not to use the screw but to use the pestle I will do myself the pleasure of Complying with your future wishes
RC (DLC); endorsed by TJ as received 31 Mar. 1811 and so recorded in SJL.
1. Manuscript: “scrws.”