An Atmospheric i’ump.

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Otiap. t>.

siphon; and one to which the remark of Switzer only can apply—“ the si-phon was undoubtedly the chief instrument known in the first ages of theWorld, (besides the draw-well) for the raising of water.”“ *

Nor is there any thing in the account given by Vitruvius of ‘the Ma-chine of Ctesibius,’ which indicates that the atmospheric pump was not inprevious use. His description is obviously that of a forcing pump, (andappears to have been so understood by all his translators,) one whoseworking parts were placed not above but in the water it was employedto elevate; whose piston was solid, and which by ineans of pipes forcedthe water above üself; that raised the water “very high;”—attributeswhich do not belong to the common pump. It is true he has not men-tioned the latter, perhaps because it was not then employed as now incivil engineering, and therefore not within the scope of his design in wri-ting his work. The manner in which Pliny speaks of it, shows that itwas an old device in his time, since it was one with which even country-people or farmers, (the last to adopt new and foreign inventions) were fa-miliär. In his 19th Book , ‘ On Gardens,’ cap. 4, he observes: when astream of water is not at hand, the plants should be watered from tanksor wells, the water of which may be drawn up by plain poles, hooks andbuckets, by swapes or cranes, [windlass] “or by pumps and such like.”And that these were no other than the old wooden pump of our streetsand such as our farmers use, is obvious from a passage in his 16th Book ,cap . 42, where speaking of the qualities and uses of different kinds ofwood, he remarks, “ pines, pitch trees and allars, are very good to makepumps and eonduit pipes to convey water; and for these purposes theirwood is bored hollow.”

Although sufficient time may be supposed to have elapsed from the ageof Ctesibius to that of Pliny for the introduction of the atmosphericpump to the countrymen of the latter, (supposing it to have been inventedby the formier) we can hardly believe, if it were not of more remoteorigin, that it could even m that time have found its way into Romanfarm-yards and gardens; much less that it should have superseded, (as itappears to have done) every other device on board of their ships. Newand foreign inventions were neither circulated so easily nor adopted soreadily in ancient as in modern days; and even now a long time wouldelapse before inventions of this kind would find their way through theWorld and longer before they became generally adopted. But had thepumps of which Pliny speaks been of recent introduction, he would cer-tainly have said so; and had they been the ‘water forcers’ of Ctesibius ,to which he alludes in his 7th Book , he could scarcely have avoided re-cording the fact.

That the antlia was the atmospheric pump would also appear from itsemployment in ships. There is no reason to suppose that more than threekinds of marine pumps were ever in use—the chain pump, the screw, andthe common pump. In the chapter on the former we have shown that itwas not known or used by the Greeks and Romans. The screw w'as firstadopted as a ship pump by Archimedes , (see page 133) and hence itwould seem that the last only could be intended by more ancient as wellas subsequent authors when speaking of the antlia: that it was so, anti-quarians generallyadmit. “The well, (says Fosbroke in his article on thevessels of the classical ancients) was emptied by the winding screw ofArchimedes now in use ; but in other ships by the antlia or pump.” It isof the latter that Pollux speaks, and to it Tacitus refers when mentioning

a Hydrostatics, ‘294.