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' LII. Notices respecting New Books. 



A Treatise on Statics, containing some of the fundamental propositions 

 in Electrostatics. By Geoege M. MiNCHiN, M.A., Senior Mode- 

 rator in Mathematics and Naturcd Philosophy, Trinity College, 

 Dublin, and Professor of Applied Mathematics in the Royal Indian 

 Engineering College, Cooper s Hill. London: Longmans, Green, 

 and Co. 1877. (Crown 8yo, pp. 450.) 



nPHIS work contains all those parts of Statics which are commonly 

 -*- read by students. It is found, we believe, that comparatively few 

 continue their inquiries into the parts of the subject that are here 

 omitted — such as the Equilibrium of Structures and Machinery, 

 and that of Elastic Solids. 



The work is divided into fourteen Chapters, of which the first 

 eight are much more elementary than the last six. These eight 

 chapters contain a very full discussion of the composition and reso- 

 lution and of the equilibrium of forces acting in one plane on a 

 point or on a rigid body. Each of these subdivisions is fully 

 treated. E. g. distinct chapters are devoted to questions in which 

 surfaces of contact are supposed to be smooth, and to questions in 

 which they are supposed to be rough ; a distinct section is allotted 

 to a discussion of the principle of virtual velocities, or (as Mr. 

 Minchin prefers to call it) the principle of virtual work, in the case 

 in which the forces act on a point, and another section to the case 

 iu which they act on a system of two connected points. These two 

 sections form one chapter ; a second chapter is devoted to the ap- 

 plication of the principle to the case in which the forces act in one 

 plane on a rigid body. 



The last six chapters are, as already stated, of a less elementary 

 character than the first eight. They treat, successively, of the 

 equilibrium of a body under the action of any forces, of the 

 determination of centres of gravity, of the application of the prin- 

 ciple of virtual work to any system of bodies, of the equilibrium of 

 flexible strings, of simple machines, and of attractions. There is 

 no need for dwelling at length on this list of contents ; but it may 

 be noted that several kinematical theorems relating to the dis- 

 placement of rigidly connected points are given in the chapters 

 treating of virtual work, and that the question of the stability 

 or instability of equilibrium is discussed more fully than is usual 

 in works of about the same scope as the one before us. The chapter 

 on Attractions consists of three sections : in the first the properties 

 of the Potential are investigated and applied to various elementary 

 questions of attractions ; in the second the attraction of the Ellip- 

 soid is treated ; and in the third, on " superficial distributions," 

 Green's Equation is proved, and the subject of Electrical Images 

 briefly noticed. 



The whole of the work — but particularly the first eight chapters 

 — is illustrated by very numerous examples, many of which are 

 fully and many others partially worked out. They are a very valu- 

 able part of the work, and the more so as they are made to illus- 



