Thomas Jefferson Papers

To Thomas Jefferson from Robert R. Livingston, 1 August 1790

From Robert R. Livingston

ClerMont 1st. Augt. 1790


Having flattered myself that I had fallen upon a new meathod of diminishing the friction in heavy machines, I take the liberty to communicate it to you, and to beg that you would do me the favour to inform me if I have deceived myself, or made a useful discovery?

Let the end of the spindle pass thro, and be strongly fixed to a peice of light wood whose solid contents should be two square feet and whose length should be twice its breadth. Let the point of the spindle be fixed in a vessel large enough to receive it with its cylinder, leaving a space of ⅛ of an inch at the side and ¼ of an inch at the bottom, between itself and the cylinder. Fill this space with quicksilver a cubick foot of which weighs 947. If then the pressure on the spindle should be 2000 per. the weight on the point of it will be reduced to 106, the rest being supported by the bouyancy of the wood. The little friction that may exist between the mercury and the sides of the vessel will be more than compensated by reducing the point of the spindle, which in this case will not bear 1/10 part of the weight necessary if no quicksilver was used. You will easily see sir, that this principle (if not erronious) may be applied to every species of fixed machines, and that in many cases water may be made to answer the purpose of quicksilver.—I have the honor to be Sir with respect & esteem your Most Ob. Hum. Servt.,

R. R. Livingston

RC (DLC); endorsed by TJ as received 5 Aug. 1790, but recorded in SJL under 4 Aug.

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