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Hydraulics.

than at the io ,h of June. Lastly, that th 1greateji Spring Tides happen not at the i o th °JMarch, and 12 th of September, but in FebWary and Qctober, is because the Sun beist£nearest the Earth in December , his Influentis then strongest, and so must quickenTime of the greatest Vernal Tides ; and Wing weakest in June , the Time of thetumnal Tides will necessarily be retarded.

Such are the Phenomena of the Ti^according to a general Theory, and ^found to be verified in those Parts of ^Earth’s Surface which are wholly coves 61with Water, as the Theory requires; *mean the vast Atlantic and Wefern Oce$ S(LXXXIV.)

in large Quantities, so as by Conduct-Pipes to cha^large Guns therewith, at a Distance from the LteaVessel; yet something of this Kind maybe effected’ Jfexpanding a small Quantity of Water at the Botton 1the Cannon into Vapour, by first' putting a red-hot stBullet down the Bore to the Water, which it soonpates into Vapour, and when confin’d at the T° uC ( jhole, and another with which the Cannon is chatg 6 ^it will soon become strong enough to drive it,with I fenough for any proposed Effect. So that the Steam's jyor even a Steam-Cannon , is perhaps a matter not m eJ (in pojfe, but may be hoped for in Reality, if all ss^lExpedients be tried, and Experiments made for that *pole. . (

(LXXXIV.) x. The Theory of the Tides isof great Curiosity, and Importance, and has th eie ^^excited several learned G entlemen to endeavour an ^

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p’anation thereof, in such Ways, as they think th^^nous Phjejipmena will be best and most easily v ’l°A

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