MATHEMATICS. 



The object of the author is to present the subject as a continuous 

 chain of argument, separated from all accessories of explanation 

 of illustration. All such explanation and illustration as seemed 

 necessary for a beginner are introduced either in the form of 

 foot-notes, or, where that would have occupied too much room, of 

 Appendices. 



Earnshaw (S., M.A.) PARTIAL DIFFERENTIAL 



EQUATIONS. An Essay towards an entirely New Method of 



Integrating them. By S. EARNSHAW, M.A., of St. John's 



College, Cambridge. Crown 8vo. $s. 



The peculiarity of the system expounded in this -work is, that in every 

 equation, whatever be the number of original independent variables, 

 the work of integration is at once reduced to the use of one indepen- 

 dent variable only. The author's object is merely to render his 

 method thoroughly intelligible. The various steps of the investiga- 

 tion are all obedient to one general principle : and though in some 

 degree novel, are not really difficult, but on the contrary, easy when 

 the eye has become accustomed to the novelties of the notation. Many 

 of the results of the integrations are far more general than they were 

 in the shape in which they appeared informer Treatises, and many 

 Equations will be found in this Essay integrated with ease in finit e 

 terms, which were never so integrated before. 



Ferrers. AN ELEMENTARY TREATISE ON TRILINEAR 

 CO-ORDINATES, the Method of Reciprocal Polars, and the 

 Theory of Projectors. By the Rev. N. M. FERRERS, M. A., Fellow 

 and Tutor of Gonville and Caius College, Cambridge. Second 

 Edition. Crown 8vo. 6s. 6d. 



The object of the author in writing on this subject has mainly been to 

 , place it on a basis altogether independent of the ordinary Cartesian 

 system, instead of regarding it as only a special form, of Abridged 

 Notation. A short chapter on Determinants has been introduced. 



Frost. Works by PERCIVAL FROST, M.A., late Fellow of St. 

 John's College, Mathematical Lecturer of King's College, Cam- 

 bridge : 



THE FIRST THREE SECTIONS OF NEWTON'S PRIN- 

 CIPIA. With Notes and Illustrations. Also a Collection of 

 Problems, principally intended as .Examples of Newton's Methods. 

 Second Edition. 8vo. cloth. JQS. 6d. 



