INTRODUCTION. 



THE analytical table of contents, which the reader must have 

 perused, will have shown him that this volume is not a selection 

 of shreds and patches, garbled from contemporary authorities : 

 but a systematic treatise on Hydrostatic Science, containing a 

 vast mass of valuable and interesting facts, combining indeed 

 almost all that needs to be known on the equilibrium of fluids. 

 But for the convenience of reference, these Mechanics of Fluids 

 are distributed into a series of chapters, whose titles indicate 

 the several topics that receive mathematical demonstration. 

 The first of these contains, besides a few brief but necessary 

 definitions, the fundamental proposition upon which all the pro- 

 blems that are drawn up in Elementary Hydrostatics are in 

 reality founded. 



The principle established in the general proposition, enables 

 the reader to proceed in the second chapter with the pressure of 

 incompressible fluids upon physical lines, rectangular parallelo- 

 grams considered as independent planes immersed in the fluid, 

 and to determine the position of the centre of gravity of the 

 various rectangular figures which the successive problems em- 

 brace, together with the pressures of fluids upon the sides and 

 bottoms of cubical vessels, with the limits which theory assigns 

 to the requisite thickness of flood-gates. 



One distinguishing characteristic in this inquiry is, that every 

 problem is accompanied by a practical example ; and in order that 

 nothing be omitted which could render the subject intelligible to 



VOL, i. c 



