CRITICAL NOTICES OF NEW PUBLICATIONS. 327 



experience^ to be the chief stumbling-blocks in the way of those who 

 seek popularly for instruction. * * * I bave endeavoured to 

 point out how, by the application of those common means of mea- 

 suring and of weighing with which every one is familiar, we may 

 arrive at a knowledge of the distances, the magnitudes, the masses, 

 and the motions, of all the heavenly bodies, or be able to state, with 

 certainty, that their distances are beyond all mensuration. I have 

 endeavoured, for the first time, I believe, to explain, in common 

 language, the law of the planetary motions ; to analyze the balanc- 

 ing forces which sustain the heavens into their simple elements ; 

 and to show which of these elements are constant, and which admit 

 of variation. * * * In order to get a foundation, I have shewn, 

 using some diagrams in illustration, the impossibility of the earth 

 being a plane surface ; I have endeavoured to point out the errors 

 of distance, magnitude, and motion, both on the earth and in the 

 heavens ; I have attempted to shew, from first principles, the na- 

 ture and stability of motion in an elliptic orbit ; and because I have 

 always found the change of distance and of rate which takes place 

 in the perihelion and the aphelion to be one of the perplexities, I 

 have laboured this point with no inconsiderable degree of attention. 

 If the reader shall collect and carry forward the remarks as far as 

 the ninth section, he will be able to see how the general principles 

 are made to bear upon what is practically observed ; and that our 

 knowledge of the heavens, as expressed in numbers, rests on a surer 

 foundation, and is as accurate, as any similar expression in the most 

 familiar business of life." 



Thus clearly and concisely does JMr. Mudie expound his object, 

 and we must say that he has carried it into effect, throughout the 

 whole of his pages, in a style the most lucid and convincing. Ten 

 sections comprise the analysis of the contents, and they form a mass 

 of information and instruction which it would be difficult to find 

 equalled in any other single publication, however voluminous. The 

 typography is extremely neat and more than usually correct, and 

 the general appearance is, altogether, of a very superior order. This 

 volume, which corresponds with the others, is, also, illustrated with 

 a frontispiece and vignette, in which Baxter's beautiful art of print- 

 ing in oil colours is shewn to peculiar advantage. 



On the Natural History and Classification of Quadrupeds. By 

 Wm. Swainson, A. C. G., F. R. S. & L. S., &c. : forming a vol. 

 of The Cabinet Cyclopcedia. London: Longman & Co. Pater- 

 noster-row, and Taylor, Upper Gower-street. 1835. 



Independently of the correct and admirable classification which 

 so pre-eminently distinguishes this volume, there is a philosophic 

 spirit breathing throughout its pages, which few writers on this in- 

 teresting subject have introduced with such cogent and felicitous 

 effect. 



The first Part, comprehending the great divisions of organized 



