Q.A801 

 Fes 



ADVERTISEMENT. 



IN selecting materials for this treatise particular re- 

 gard has been had to the practical uses of the science ; 

 at the same time the theoretical principles are rigorously 

 demonstrated. Where the nature of the subject ad- 

 mitted of it, the geometrical method has been pre- 

 ferred, as being more perspicuous and better adapted to 

 most learners. There are many refinements in the 

 later and more improved treatises not adopted in this, 

 for the reasons above mentioned, and on account of the 

 insufficient provision, as to time and preparatory studies, 

 that is made in most of the seminaries of the United 

 States for a text-book upon such a plan. 



The works principally used in preparing this treatise 

 are those of Biot, Bezout, Poisson, Francoeur, Gregory, 

 Whewell, and Leslie. In the portions selected it was 

 found necessary to make considerable alterations and 

 additions in order to give a uniform character to the 

 whole. There has often been occasion, moreover, in 

 appropriating the substance of a proposition or course of 

 reasoning, to amplify or condense it, or to vary the 

 phraseology. It became inconvenient, therefore, to dis- 

 tinguish by quotations the respective portions taken 

 from different authors. Bezout has been adopted, in 

 substance, as the basis in what relates to statics, dynam- 

 ics, and hydrostatics, although the matter is arranged 



