Chap. 2.] [ 401 ] 



C H A P. II. 



HYDROSTATICS. 



'Difco-veries of Archimedes in this B>- finch of Science. Of the Moderns. 

 Hoiv Fluids are titled upon by the general Laws ofGravifaticn. 

 Particles of Fluids aJi independently of each other. Experiment 

 efcertaining this Principle. Fluids frefs equally in all Directions. 

 Cautions neceffary in conftruding Aquedutls, &c. to guard agair.Jl 

 the lateral Prejjiire of Fluids. All Parts of the fame Fluid in Equi- 

 librium --with each other. -> Surfaces of Fluids always in a Plane 

 parallel 'with th's Horizon, Prfffwe of Fluid* in proportion to their 

 Height. Hydroji-atic Paradox. Effects of Gravity on Fluids of 

 different 'Denfttics.> Action of Air on tfe Surfaces of Fluids. Uje 

 cf a Vtnt Peg. The Valemis The Siphon. Attion if Fluids on 

 f olid Bodies immerfed in them. Why ctrtain Bodies Jink and others 

 Jhvirn in certain Fluids. Bodies thai fivim difpldce a Bulk of IV at er 

 equal to tketnfclves in Weight but net in Magnitude. The fame Body 

 luill jink in one Fluid, which ivillfwim in another. The Hydro- 

 meter. Fahrenheit' 's Hydrometer. Recapitulation of the Dotirines 

 refpecli-ng fpecijic Gravity. Honv to wak a Globe cf Iron fwim tn 

 the Surface of Water. Boats made rf Capper. 



WAT E R, as a fluid, has certain properties* 

 which, though common to all nnelaftic or in- 

 compreffible fluids, are ufually confidered under this 

 topic; and indeed the fciences of hydroftatics and 

 hydraulics, which regard thefe properties, immediately 

 derive their names from that fluid *, on which the 

 experiments, illuftrative cf them, are ufually made. 



Hydroftatics have for their object the weight and 

 prefiure of fluids - 3 and in this branch, of fcience the 



* "f$v ? (Hydor) water, and o-1*7x>; (ftatike) the fcience of 

 weight. Hydraulics from \^and attof (au]os) a. tube or pipe. 



VOL, II. D d art 



