522 Notices of Books. [October, 



at 50. Under these conditions, the colours of the spectrum are 

 approximately as follows : — Red to 48, yellow to 52, green to 80, 

 blue to 120, and violet beyond. 



A Dictionary of Terms Used in Architecture, Building, Engi- 

 neering, Mining, Metallurgy, Archaeology, the Fine Arts, 

 &>c. By John Weale. Fourth Edition, with Numerous 

 Additions. Edited by Robert Hunt, F.R.S. London: 

 Lockwood and Co. 1873. 

 When a work has so rooted itself in our literature as to reach a 

 fourth edition, the business of a reviewer becomes tolerably 

 simple. Indeed the public has long ago formed its own opinion 

 as to the merits of the work ; and the very existence of the 

 successive editions bespeaks its value more clearly than any 

 favourable expressions that may fall from the reviewer's pen. 



The rapid growth of modern science, and the consequent ex- 

 tension of scientific terms to the various branches of industry 

 and art, renders it more than ever necessary that we should con- 

 stantly have at hand some trustworthy work of reference on 

 technical nomenclature. It is difficult to point to a handier 

 book for this purpose than Weale's well-known Dictionary ; it is 

 comprehensive, though small, and is, indeed, just the book which 

 one may confidently consult when seeking the interpretation of 

 some obscure word in the language of our industrial arts. 



The present edition of Weale's Dictionary has had the benefit 

 of careful revision by Mr. Robert Hunt, whose long experience 

 with kindred literature leads him to know exactly the kind of 

 matter which the public seeks and expects to find in a work of 

 this character. The editor has judiciously adopted, in preparing 

 this edition, a more systematic arrangement of the matter ; and, 

 by omitting the biographical sketches which appeared in the 

 earlier editions, has contrived to squeeze in a goodly amount of 

 new matter without increasing the bulk of the book. 



A rapid glance down the columns of this Dictionary is suffi- 

 cient to show that even the best informed amongst us may often 

 turn with profit to its technical definitions. Take, as accidental 

 examples, the first and last words in this Dictionary ; — surely it 

 is not everyone who, if suddenly called upon, could give a satis- 

 factory definition of either A am or Zyghar. 



Celestial Objects of Common Telescopes. By the Rev. T. W. 

 Webb, M.A., F.R.A.S., Vicar of Hardwick, Herefordshire. 

 London : Longmans, Green, and Co. Third Edition, Re- 

 vised and Enlarged., 

 It is gratifying to learn that such a book as this has reached 

 a third edition. It is not a library book, is by no means likely to 



