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Ascent of Water in Pumps incomprehenstble [Book II,

while he could find no apparent communication between them 1 Thefactisit would be difficult for him to point out any closer Connection betweeuthe pump rod and the water in the well, than between a walking cane inthe hands of a pedestrian, and water under the surface of the groundover which he stepped ; nor could he assign a conclusive reason, why theliquid should not ascend and accompany the movements of the latter aswell as of the former.

He could perceive no obvious or adequate cause for the elevation ofwater through the pipe of a pump, there being no apparent force appliedto it, or in the direction of its ascent, no vessel or moveable pallet goingdown, as in the preceding machines, to convey or urge the liquid up—andhence he could no more comprehend how the movements of a pump box(sucker) above the surface of the ground, should induce water in a wellto rush up towards it, than he could explain how the waving of a magi-cian’s wand should cause spirits to appear.

Long familiarity with the atmospheric pump, makes ithard forus, atthepresent day, to realize the difficulties formerly experienced in accountingfor the ascent of water in it. Suppose the cause yet unknown arid un-thought of—it certainly would puzzle us to explain how a piece ofleath-er (the sucker) moving up and down in a vertical tube, whose lower ori-fice is in water, some twenty-five or thirty feet below it, should conjurethat water up. Such a result is opposed to all experience and Observa-tion in other departments of the arts ; nor is there any thing like it, in themachines we have examined in the preceding book. The meehanism bywhich motion is transmitted from them to the water, is obvious to thesenses—-a tangible medium of communication is established between theforce that Works them and the water they raise ; whereas in the pump, aninvisible agent is excited, whose effects are as surprising as its mode ofOperation is obscure. ’Tis true, a tube (the pump pipe) is continued fromthe place where the sucker moves to the water, but it remains at rest, oris immoveable, and therefore cannot transmit motion from one to the other;it is merely a channel through which the water may rise—it does notraise it.

But if, in Order to establish a connection between the sucker and water,the former were made to descend through the pump into the latter, stillthe difficulty would not be overcome. The sucker in that case would actmuch like one of those buckets, used in some Wells , which has an openingin its bottom to admit the water, and covered by a flap to prevent itsreturn. (The sucker is in fact, merely a small bücket of this kind, and isso named in some countries.) In both cases the water would be raisedwhich entered through the valves—the bücket would bring up all it con-tained, and the sucker all that passed through it into the pump; so far tbeOperation of both is clear, and as regards the raising of the water abovethe valves, would be the same ; but it is the ascent of a column of waterbekind the sucker that requires explanation—a liquid column that followsit as closely through every turn of the tube, as if it were a rope, havmgits fibres at one end fastened to the sucker and pulled up by it. hat

is it that mäkes this water ascend against a law of its nature—agamstgravity 1 Were the cohesion of its particles such that it could be raisedby a force applied only to its upper end, then indeed the difficulty would bediminished but in that case, it would follow that a similar column wouldascend after a hucket when drawn out of an open well; and further, thata traveler might then rn ake üse of a liquid walking stick, to assist him inhis journeying.

Baffled thus in our attempts to find a solution here, we perhaps would