PART H. 



MACHINERY IN CONNECTION WITH WATER. 



GENERAL PRINCIPLES. 



Hydkostatics * treats of the -weight and pressure of 

 liquids when not in motion ; HYDEAFLics,f of liquids in 

 motion, as, conducting water through pipes, raising it by 

 pumps, etc. ; and Hydrodyxamics J includes both, by 

 treating of the foixes of the liquids, whether at rest or in 

 motion. 



CHAPTER I. 



HYDROSTATICS. 

 XJPWARD PRESSURE. 



A remarkable property of liquids is their pressure in 

 all directions. If wc place a solid body, as a stone, in a 

 vessel, its weight will only press upon the bottom; but if 

 we pour in water, the water will not only press upon the 

 bottom, but against the sides. For, bore a hole in the 

 side, and the side pressure will drive out the water in a 

 stream ; or bore small holes in the sides and bottom of 

 a tight wooden box, stopping them with plugs ; then press 

 this box, empty, bottom downward, into water, allowing 

 none to run in at th6 top. INow draw one of the side 

 plugs, and the water will be immediately driven into the 



* From two Greek words, hudor^ water, and statos^ standing, or at rest, 

 t From two Greek words, hudor, water, and aidoft, a pipe. 

 X From two Greek words, hudor, water, dunamis, power. 

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