Notices respecting New Books, 265 



various substances, we cannot pass over, in each of these 

 discoveries, immediate applications, which ought no longer 

 to be neglected. Physiology must necessarily derive great 

 advantages from attending properly to such results. 



LI. Notices respecting New Books. 



A Treatise of Mechanics, Theoretical, Practical, and De- 

 scriptive. 5y Olinth us Gregory, of the Royal Mi^ 

 litary Academy, Woolwich. 2 Fols. 8vo, and a Volume 

 of Plates. Published ly Kearslcy. 



J.T is with much satisfaction we announce the publicatloa 

 of a work of this nature, which has been long wanted. 



The first volume, is devoted chiefly to theory ; the second 

 is practical and descriptive. The theoretical part is divided 

 into five books, and these arc subdivided into chapters, as 

 the nature of the several subjects seemed to require. 



Book I. is appropriated to the subject of statics, and is 

 subdivided into six chapters. It commences, as indeed do 

 all the books, with definitions and preliminary remarks j 

 which arc succeeded by a statement and illustration of the 

 Newtonian laws of motion and rest, which are assumed as 

 fundamental principles to guide the subsequent inquiries. 

 The nature of statical equilibrium, with the composition and 

 resolution of forces, are then discussed ; forces bcins; con- 

 sidered, 1. as disposed in one plane, and concurrino; in the 

 same point : 2. as directed to one point, but not confined to 

 one plane : 3. as situated in one plane, but applied to diffe- 

 rent points of a body : 4. as not confined to one plane, and 

 directed to various points of a body. The remaining chapters 

 in this book treat of the centre of gravity, and the centro- 

 hdsyc method ; the simple machines, or, as they arc usually 

 called, the mechanical powers; the strength and stress of 

 timber and other materials; and the equilibrium, tension, 

 and pressure of cords, arches, and domes. The minuter 

 topics connected with these general points of inquiry can- 

 not well be specified here. 



The 



