File:Notes on Virginia - syphon fountain diagram.jpg

English: We are told that during a great storm on the 25th of December, 1798, the Syphon Fountain, near the mouth of the North Holston, ceased, and a spring broke out about 100 feet higher up the hill. Syphon fountains have been explained by supposing the duct which leads from the reservoir to the surface of the earth to be in the form of a syphon, a, b, c, where it is evident that till the water rises in the reservoir to d, the level of the highest point of the syphon, it cannot flow through the duct, and it is known that when once it begins to flow it will draw off the water of the reservoir to the orifice a, of the syphon. If the duct be larger than the supply of the reservoir, possibly the force of the waters and loosening of the earth by them, during the storm above mentioned, may have opened a more direct duct as from e to f, horizontally or declining, which issued higher up the hill than the one fed by the syphon. In that case it becomes a common spring. Should this duct be again closed or diminished by any new accident, the syphon may begin to play again, and both springs be kept in action from the same reservoir.