Let G G′ be a pipe entering the sides of the vessels V and V′, for the purpose of filling them with the water to be raised: let K be a cock having a curved passage similar to the cock R, and leading to a tube by which water is supplied from the reservoir or other source from which the water to be raised is drawn. When the cock K is placed as represented in _fig._ 4., the water from the reservoir will flow through the curved passage in the cock K into the tube G′, and thence into the vessel V′; but when this cock is turned one quarter round, by shifting the lever to the left, it will take the position represented in _fig._ 6., and the water will flow through the curved passage into the tube G, and thence into the vessel V. Let us now suppose the vessel V already filled with water to be elevated, and the vessel V′ to have discharged its contents. The cock R is turned, so as to allow the steam generated in the boiler E to pass into the tube T, and thence into the upper part of the vessel V, while the cock K is turned so as to allow the water from the reservoir to pass into the tube G′, and thence into the vessel V′. The steam collecting in the upper part of the vessel V′ presses with its elastic force on the surface of the water therein, and forces the water upwards in the tube C; it passes through the valve B, which it opens by the upward pressure received from the action of the steam, and thence into the tube F, its descent into the tube C′ being prevented by the valve V′, which can only be opened upwards. As the steam is gradually supplied from the boiler E, the water in the vessel V is forced up the tube C, through the valve B, and into the tube F, until all the contents of the vessel V above the lower end of the tube C have been raised. In the meanwhile, the vessel V′ has been filled with water, through the cock K: when this has been accomplished, the man who attends the machine shifts the cocks R and K, so as to give them the position represented in _fig._ 5. and _fig._ 6. [Pg033] In this position, the steam from the boiler, being excluded from the tube T, will be conducted to the tube T′, and thence to the vessel V′, while the water from the reservoir will be excluded from the tube G′, and conducted through the tube G to the vessel V. The vessel V will thus be replenished and, by a process similar to that already described, the contents of the vessel V′ will be forced up the tube C′, through the valve B′, and into the tube F; its descent into the tube C being prevented by the valve B, which will then be closed. After the contents of the vessel V′ have thus been raised, and the vessel V replenished, the two cocks R and K are once more shifted, and the contents of V raised while V′ is replenished, and so on. [Illustration: _Fig._ 4, 5, and 6.]