City of Washing
Sept 26th 1808.
in the winter of 1806, you may recollect of my visiting you at the Presidents palace; & that without a previous acquaintance, or letters of introduction the reason was, that I thought the introduction wou’d be as Satisfactory on both parts, by the Subject alone as by letters: Mr Dufief particularly offered me a letter, but I considdered it intirely unnessary for the reason before mentioned; he then told me that he had no introduction. & Sir I believe it made kind of difference.—if you recollect my purpose was, to make an improvement on the mode of Communicateing motion: at that time I thought I had Compleated it, but Since I have found that I only Commenced it, for, not untill lately have I brought the affair to a Close.—I now prepose a revolution in the present System of Communicating motion; & if my principles be Correct it also will produce a revolution in the System of Mechanics—as far as I have experimented my principle is Correct; on the windmill particularly I have applied the principle to the Sails, & from that alteration I find that Twenty yards less will answer in the hundred the Same purpose. I have not applied it as runing gear to my windmill, but I have to a grindstone with equal effect.—the Screw is the power with which I produe motion to the most advantag in every Case, either by water, wind, Steam, or in any other way that motion is to be produced. I will Say no more on the Subject now, but hope & pray that you will give me permission to lay the whole before you.—I have been on the Subject of Mechanics for more than Six years; your knowledge of geneal principles is So extensive, that I know I Should receive more Satisfaction in communicating with you than any other person in the world Should I be mistaken I wish to know it & if I am not, I wish to know it also. if through any motive whatever you Should decline answering me, I Should never forgive my self for writing to you. figure to your Self a young man Scarcely more than Twenty five years of age, who has been, & Continues be anxious to benefit Philosophy, who has Secluded himself from the world & devoted himself to its Study. Mr Dufief told me that you were always ready to correspond with or See, a deep thinking man; I am Confident I am one of that Class, whether my thoughts will turn to the advantage of Society or not. be Assured that no man esteems your Excellency more than I do.
David K. Hopkins
NB. if you write, have the goodness to direct it to the care of Matthew Hopkins Esqr Snow Hill Maryland.
D. K. Hopkins
DLC: Papers of Thomas Jefferson.