Siphon and Funnel Device
This was the work of an Englishman whose name is unknown. An account of it appeared in "Mechanics' Magazine," 1828, in the following language:
a is a circular glass vessel 1 foot 6 inches diameter; b b a tube fixed thereunto; c c are funnels containing valves; d, a float of hollow copper, or any light substance; e, an open mouth; f, an open vessel filled with mercury as high as the dotted line.
It is well known that several experiments were made by M. Venturi, Sir Isaac Newton, etc., demonstrating that a vessel shaped thus—
will emit water with a much greater rapidity than a vessel shaped thus—
say, with more than a third as much speed. I propose, then, to have the mouth of the vessel a of the former shape, being the natural form of flowing water. The vessel a, and tube b, must be completely filled with mercury, by means of the funnels c c, which will also contain mercury. In order to set the fluid in motion, the valve in the large vessel c is to be raised; the mercury (which was hitherto held up by a greater weight of atmosphere) will instantly run out of the mouth e, and must be suffered to do so till the mercury in c is level with the dotted line; by this time the mercury in a will have obtained a momentum which will be more than equivalent to the pressure of the atmosphere: consequently, the mercury will run out of the large vessel a, till it falls as low as the dotted line; the float d, resting on the mercury, of course, falls with it, opens the valve, and admits a proportionable quantity of mercury through the tube b, driven by the pressure of the atmosphere (the height from the mercury in f, to the top of the tube b, being only 26 inches, which is 2 inches less than what the atmosphere will at all times raise mercury in a vacuum).
By this means will there not be a continual circulation of mercury?
