Thomas Jefferson Papers

To Thomas Jefferson from Littleberry H. Mosby, 30 April 1824

Powhatan County 30th of April 1824

[GRAPHIC IN MANUSCRIPT]The A’s represent 4 reservoirs, B’s. 4 pumps fixed in the ordinary way, C’s the levers to the pumps, D’s a rod connecting the levers together, with joints where it is attached to the levers; this is to accommodate it to the motion of the levers moving up and down: (or a chain would answer and would be probably better) E the place where the water is delivered, F, the fulcrum, and beam to work the connecting rod or chain, G the crank, by which the whole is worked. H.H the sides of the well.—When therefore the shaft or beam to which the crank is fixed is put in a rotatory motion, the whole of the pumps are worked. The first pump raises the water to the first reservoir and is then taken to the second reservoir by the second pump and so on as is wished. It will be at once seen, that the water is raised when the connecting rod or chain is descending and of course it must be of sufficient weight to overcome the whole of the resistance required to raise the water—The pumps are calculated to be 30 feet in length, the medium height to which the atmospheric pressure will support a column of Water.—The annexed sketch is therefore calculated to raise water 120 feet:

 The question then is: whether it will be easier to raise it in the way proposed or in a solid column 120 feet.

Mr Jefferson will oblige the undersigned, if he will at some convenient time give his opinion, on the question proposed—

Littleberry H. Mosby

MoSHi: Thomas Jefferson Collection (formerly Bixby).

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