VOL. XT .3 PHILOSOPHICAL TRAMSACTIOMS. , ' 251 



water would be raised to the intended height : such receptacles might easily be 

 set ] 2 or 1 5 feet above one another, and so a few of them might raise water 

 to a considerable height, as well as ordinary pumps do ; but this new way 

 would have this advantage, that whereas in the ordinary pumps, the strength to 

 be applied lies near the water to be raised, but by this contrivance the stream 

 of a river may be applied to draw water out of a mine far distant from it: by 

 the same way the stream of the Thames might keep constant water-works in 

 Windsor Castle, almost as easily as in the lowest fields. It is also to be ob- 

 served, that those bellows that are open, have the air in them very much rare- 

 fied, so that the outward air lies heavy upon them to shut them, by which 

 means the motion of the engine must be helped in lifting up the opposite bel- 

 lows, to be opened. 



jis a further Explanation of the Use of this Contrivance, in fig. 6, pi. 8. — 

 AB, AB, are several receptacles set above one another, which must be well 

 shut and soldered every where. CDD, CDD, are two slender pipes, by which 

 the first and third receptacles communicate with the pump HH. EFF, EFF, 

 two other slender pipes, by which the second and fourth receptacles have a com- 

 munication with the pump II. HH, 1 1, two pumps, whose plugs are so moved 

 by the axis LL, that when one descends the other ascends. MM, a wheel 

 fastened to the axis LL, that it may be moved by the stream of a river. NO, 

 PQ, NO, PQ, are large pipes for the water to ascend, from a lower to a 

 higher receptacle. O, Q, O, Q, are valves fitted to the top of the said pipes, 

 to prevent the water from descending. 



Now it is plain that when the plug in the pump HH ascends, the air comes 

 in through the pipes CDD, by which it is rarefied in the first and third recepta- 

 cles, marked A A: by which means the water may be driven up into the recep- 

 tacles through the pipes NO; because at the same time the plug in the pump 

 II descends, it causes the air to return to its ordinary pressure in the second 

 and fourth receptacles, that it may be capable to force up the water through 

 the said pipes NO, and the lowest pipe draws the water that lies open to the 

 air. For the same reason, when the plug in the pump 1 1 ascends, the air must 

 come in through the pipes EFF; and so be rarefied in the second and fourth 

 receptacles marked BB; by which means the water is forced up into the said 

 receptacles through the pipes PQ, PQ; because at the same time the plug in 

 the pump HH descends, it causes the air to return to its ordinary pressure in 

 the first and third receptacles, so that it is enabled to force up the water through 

 the said pipes PQ. 



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