io SCIENTIFIC CATALOGUE. 



comprise the following : An Essay on the application of Mathe- 

 matical Analysis to the Theories of Electricity and Magnetism 

 On the Laws of the Equilibrium of Fluids analogous to the Electric 

 Fluid On the Determination of the Attractions of Ellipsoids of 

 variable Densities On the Motion of Waves in a variable Canal 

 of small depth and ividth On the Reflection and Refraction of 

 Sound On the Reflection and Refraction of Light at the Common 

 Surface of two Non- Crystallized Media On the Propagation of 

 Light in Crystallized Media Researches on the Vibrations of Pen- 

 dulums in Fluid Media. "It has been for some time recognized 

 that Greeris writings are amongst the most valuable mathematical 

 productions we possess. " Athenaeum. 



Hemming. AN ELEMENTARY TREATISE ON THE 



DIFFERENTIAL AND INTEGRAL CALCULUS. For the 

 Use of Colleges and Schools. By G. W. HEMMING, M.A., 

 Fellow of St. John's College, Cambridge. Second Edition, with 

 Corrections and Additions. 8vo. cloth, gs. 



" There is no book in common use from which so clear and exact a 

 knowledge of the principles of the Calculus can be so readily ob- 

 tained. " Literary Gazette. 



Jackson. GEOMETRICAL CONIC SECTIONS. An Ele- 

 mentary Treatise in which the Conic Sections are denned as the 

 Plane Sections of a Cone, and treated by the Method of Projections. 

 By J. STUART JACKSON, M.A , late Fellow of Gonville and Caius 

 College. Crown 8vo. 4^. 6d. 



This work has been written with a view to give the student the benefit 

 of the Method of Projections as applied to the Ellipse and Hyper- 

 bola. When this method is admitted into the treatment of Conic 

 Sections there are many reasons why they should be defined, not 

 with reference to the focus and directrix, but according to the 

 original definition from which they have their name, as Plane 

 Sections of a Cone. This method is calculated to produce a material 

 simplification in the treatment of these curves and to make the proof 

 of their properties more easily understood in the first instance and 

 more easily remembered. It is also a powerful instrument in the 

 solution of a large class of problems relating to these curves. 



