COURSE OF LECTURES 



ON 



NATURAL PHILOSOPHY 



AND THE 



MECHANICAL ARTS. 



LECTURE XXI. 



ON HYDROSTATICS. 



I HE mechanical properties and affections of fluids, and the laws and pheno- 

 mena of their motions, are to be the subjects of the second division, of this 

 Course of Lectures. Although these properties are in reality derived from the 

 same fundamental principles as the doctrines of pure mechanics, they are yet in 

 great measure incapable of being referred, in a demonstrative and accurate- 

 manner, to the operation of simple and general causes. We are therefore fre- 

 quently under the necessity of calling in the assistance of experimental deter- 

 minations; and for this reason, as well as others, the science of hydrod3'na- 

 mics may with propriety hold a middle rank, between mathematical mechanics 

 and descriptive physics. In treating of the mechanics of solid bodies, we are 

 able to begin with axioms, or self evident truths, almost inseparable from the 

 constitution of the human mind ; to deduce from them the general laws of 

 motion, and to apply these laws, with little chance of error, to every combi- 

 nation of circumstances in which we have occasion to exarnine their conse- 

 <|uences; and it requires only a certain degree of attention and of mathema' 

 vol.. I. L 1 



