464 Review — Crystallography for Beginners. 



EEVIE "W S. 



Crystallography for Beginners, with an Appendix on the 

 Use of the Blowpipe and the Determination of Common 

 Minerals (after the Method of Dr. Albin Wbisbaoh). By 

 C. J. Woodward, B.Sc. Pp. 164, 4 Plates, and 75 Woodcut 

 Illustrations. (London : Sirupkin, Marshall, Hamilton, Kent 

 and Co., 1896.) 



THIS work consists of two parts, really independent of each 

 other : the one treats of Crystallography (100 pages) ; the other 

 (termed merely an Appendix, though extending to more than half 

 the length of the first) consists almost entirely of tables relating 

 to the determination of the more common minerals. The author 

 has avoided technicalities of expression as far as is possible, and 

 has aimed throughout at extreme simplicity of literary style, as will 

 be clear from one of the opening sentences of the First Lesson : 

 " Put into a pipkin, or an earthenware basin, about half a pint 

 of water, and add two to three ounces of the blue vitriol, 

 and heat to near boiling." In spite of the difficulty insepar- 

 able from a subject which involves the geometry of solid bodies, 

 the meaning of the author is always evident to the thoughtful 

 reader. In a brief introduction Mr. Woodward first explains the 

 method of preparing pasteboard models for the illustration of ihe 

 lessons, and supplies two plates of "nets" to be used for this 

 purpose. He then treats successively of the constancy of the angles 

 of crystals, the idea of symmetry, the systems of crystallization, the 

 notation of forms, the drawing of crystals, and the stereographic 

 projection of poles. The discussion of the physical characters of 

 crystals extends over only 15 pages, and is followed by a brief 

 account of mero-S3'mmetry. At the end of each of the nine lessons is 

 given a series of questions for the mental exercise of the student, and 

 the whole is illustrated with numerous diagrams. Although some 

 inaccuracies of statement are obvious to the critical eye, they are not 

 of a character to interfere with the general usefulness of the book. 

 The Appendix, as is stated by the author, is virtually an extract 

 from the more complete tables published by Professor Weisbach, of 

 Freiberg, and will be of service to the mineralogical beginner. 

 Sets of six illustrative specimens and some pieces of simple 

 apparatus have been prepared for issue to students using the book. 



BEPOETS J^JSTJD ZPJROO-EJEZDI^G-S. 



British Association for the Advancement of Science. Address 

 to the Geological Section by Professor J. E. Marr, M.A., 

 F.R.S., Sec.G.S., President of the Section, Liverpool, September 17, 

 1896. 



THE feelings of one who, being but little versed in the economic 

 applications of his science, is called upon to address a meeting of 

 the Association held in a large industrial centre, might, under ordinary 

 cii'cumstances, be of no very pleasant character ; but I take courage when 

 1 remember that those connected with my native county, in which we 





