314 . Notices respecting New Boohs. 



a throw from the secondary coil when the magnetizing current 

 is reversed. This throw is then compared with that obtained 

 from one of the inductors. By this method one is relieved 

 from measuring distances whose cube &c. enters into the 

 formula for reducing the observations. 



I ought not to close without acknowledging the help given 

 all through by the instrument-maker, Mr. G. Bowron, one of 

 whose workmen, Mr. Collins, suggested the convenient method 

 of release described in the paper. 



XXXIII. Notices respecting New Books. 



Annals of British Geology, 1890. By J. F. Blake, M.A., F.G.S. 

 8vo. 352 pages. Dulau and Co. London, 1891. 



npHE author, who is the President of the Geologists' Association, 

 -*■ defines this work as " a critical digest of the publications and 

 account of papers read during the year — with personal items." 

 The subject-matters are limited to notes and memoirs supplied by 

 British geologists in 1890, whether actually published, or merely 

 announced in the Reports and Proceedings of Societies as having 

 been read. In the former case careful and often full abstracts 

 are here given; and the latter (the nos. of which are enclosed 

 in square brackets) serve to indicate the lines of thought and 

 research taken by numerous observers and thinkers, the results of 

 which may be looked for in future Journals. Papers, maps, and 

 sections (657), having relation to the British Isles, are mentioned 

 at pages 1-299 ; papers on foreign Geology, published in Britain 

 (95), are to be found at pages 299-339. 



General, including physical and theoretical, Geology comes first 

 in the subdivisions of subjects ; then stratigrapkical geology accord- 

 ing to successive formations from the oldest to the newest : next 

 palaeontology, with vertebrates and invertebrates in zoological 

 order, down to sponges and microzoa ; paleobotany, mineralogy, 

 petrology, and economics succeed ; maps and sections follow ; and 

 then foreign geology as treated in British papers, in order like 

 the above. Lastly, there are what are termed " Personal Items," 

 as to the Geological and other Societies, — their Presidents, new 

 Fellows, and Awards, — also the holders of Geological Professorial 

 Chairs, — the Staff of the Geological Survey of Great Britain and 

 Ireland, and of the Geological and Mineralogical Departments of 

 the Xatural-History Branch of the British Museum, and other 

 matters. An Index of Authors, and another of Periodicals men- 

 tioned in the text, complete this comprehensive and v/ell-arranged 

 work. 



More or less complete bibliographic lists of geological books and 

 memoirs are supplied periodically in several countries (England, 

 France, Germany, Russia, United States, &c.) ; but a separate 



