Hydraulics.

Weight descend, a little cold Water,r ° m *he Fountain fg h /, is let in at the°ttom by turning a Cock at k y which, in. ° rrtl °f a Jet, condenses the hot Steam^ the Barrel into 13000 times less Spacea n before it took up, -which makes aefficient Vacuum for the Piston to descendth* o, and Lever H I, being

US put into Motion, do accordingly raisean( i depress the Piston K in the Barrel of* E forcing Pump L M on the other Side ;^uich, by the Pipe N, draws the Waterr ° m the Depth W, and forces it to rifeari d spout through the Tube O, continuedt° any Height at Pleasure. This Engineused to draw the Water from Coal-its and other Mines. Besides these, thereJlre various other Water-Engines of acomplex Structure; but as they all, t °u the same Principles with these twoCr isied, ’tis needless to fay any thing of' em here (LXXX, LXXXI, LXXXII.)

T F ire -E ngine * s ihs most ad-snd curious > and compounded Machine that wet 0 tk an 'Ss.S those whose Inventions have been owingaffo ? tJisc° ver ies of Modern Philosophy, and which■ S . greatest Advantages to Mankind. The Fire-18 two Sorts, which I shall here give thePerfects ^ an< ^ ^"'S ures of each according to the latestaboy s° n ' n w ^ich they are made. The Account givene eing only in relation to its first State and original

Simplicity;