1871J Notices of Books. 535 



written chapter on Thermo-dynamics, embodying the most 

 recent experiments, the editor claims for himself. Professor 

 Foster's nomenclature of units of heat, the gramme-degree, 

 pound-degree, &c, has been adopted. Comparing the work with 

 the French original, it is easy to see that great care has been 

 bestowed upon its production, and that much fresh matter has 

 been introduced. 



The Technical Educator; An Encyclopedia of Technical Edu- 

 cation. Volume I. Cassell, Petter, and Galpin : London 

 and New York. 



This work is a practical sequel to the theoretical lessons con- 

 tained in the " Popular Educator," published by the same firm. 

 The main subject is Drawing, with its applications to Design and 

 Ornamentation; but Civil and Military Engineering have a great 

 deal of space devoted to them ; while under a third head may 

 be considered Practical Chemistry as applied to Manufactures 

 and Agriculture. The several papers are written in a clear, con- 

 cise manner, admirably adapted to convey the amount of infor- 

 mation required by the artizan and mechanic for whom the pages 

 are intended. Too much praise cannot be afforded to Messrs. 

 Cassell for their many and successful attempts to place sound 

 elementary knowledge within the reach of the working classes. 



Annual of Scientific Discovery; or, Year-Book of Facts in 

 Science and Art, for 187 1. Edited by John Trowbridge, 

 B. Sc, Asst. Prof, .of Physics in Harvard College ; aided 

 by W. R. Nichols, Asst. Prof, of Chemistry in Mass. 

 Inst, of Technology ; and C. R. Cross, Graduate of the 

 Institute. Boston : Gould and Lincoln. London: Triibner 

 and Co. 349 pp. 



This is a resume, chiefly from the various periodicals, of the 

 most important discoveries and improvements in science during 

 the year 1870, including a list of recent scientific publications, 

 and obituaries of eminent scientific men. As a reference for 

 dates and main principles the work will doubtless be useful. 



Astronomy Simplified for General Reading. By J. A. S. Rollwyn. 

 London : William Tegg. 



The general reader who is unlucky enough to take up this 

 book with any amount of faith in its contents would be led 

 to imagine that the most exact science was a myth. Mr. Rollwyn, 

 who lives in a glass-house hypothesis of his own, is certainly 

 to be pitied for throwing stones. When an author publishes a 



