Chap. 3.] 



CHAP. III. . 



HYDRAULICS*. 



Of the Difcbarge cf Fluids through fmall Apertures. The Difcbarge. 

 of Fluids through fucce(Ji--ve Pipes. Artificial Fountains. Pumps. 

 Tbs Raifing Pump. The Forcing Pump. The Sucking Pump. 

 The Compound Pump. The Fire Engine. Motion of Water in 

 Conduit Pipes. Ofcillatory Motion cf Water in a Siphon. Ofcilla- 

 tory Motion of Waves. 'Motion of Wheels a fled upon by Water \ and 

 Conjhutlion of Water Mills. 



TH E fcience which has for its object the motion 

 of fluids is called hydraulics ; and its immediate 

 application is to furnifh us with the means of conduft- 

 ing water from one fituation to another, by canals or 

 aqueducts, and to elevate it by pumps, jets-deaux, and 

 other hydraulic engines, either for the purpofes of or- 

 nament or ufe. 



In treating of this fubje<5t I fhall commence with the 

 fimpleft principles, and mail firft fpeak of the difcharge 

 of fluids through fmall apertures. 



When water flows from a veflfel which has a hole or 

 aperture in the bottom, fmall in comparifon to the 

 width of the vefiel, the water defcends vertically, and 

 the furface appears fmooth, but at three or four inches 

 from the bottom the particles turn from this direction, 

 and proceed on all fides with a motion more or lefs 

 oblique towards the aperture. The fame efFeft takes 

 place when water flows. through an aperture late- 



* Almoft the whole of this chapter, and great part of the pre- 

 ceding, are tranflated from the firft volume of Briflbn's " Trahe. 

 Elcmentaire de Phyfique," Chap. VIII. 



rally, 



