3 6 4 



NA TURE 



[February 15, 1906 



forces, the use of a polar diagram and its application 

 to weighted beams are clearly set out. 



Door and panelled framing, revolving vestibule 

 doors, hinges and locks, and the different varieties of 

 windows, sash or casement are explained and illus- 

 trated. We cannot understand why writers on the 

 subject arc always content to show window frames 

 " in reveal " when they appear to so much better 

 advantage onlv slightly set back from the face of the 

 wall, as in " Queen Anne " and " Georgian " archi- 

 tecture, and as carried out by so many of the best 

 architects of to-day. 



There are also chapters on roof lights and con- 

 servatories, staircase work and handrailing, and 

 workshop practice, together with summaries and 

 questions from papers set at the City and Guilds ex- 

 aminations in the subject. 



OUR BOOK SHELF. 

 Die Explosivstoffe mil besonderer Berucksichtigung 

 dcr neuren Patente die Schiessbaumwolle (Nitro- 

 cellulosen). By Dr. Richard F.scales. Pp. viii + 

 308. (Leipzig: Veit and Co.) Price 10 marks. 

 This is the second volume of a series of special works 

 on explosives. Although the first volume on " Gun- 

 powder and Similar Mixtures " was issued as recently 

 as 1904, it has been found necessary to prepare a new 

 edition, and doubtless the first edition of the volume 

 under consideration will soon be exhausted. The 

 whole series when completed should form a valuable 

 n ference work on all subjects relating to explosives. 



The book is thoroughly up to date, and reference 

 will hardly be in vain for any information either as 

 to details of manufacture or the more purely scientific 

 questions relating to nitrocellulose or closely allied 

 bodies. The testing of guncottons to determine their 

 stability and the influence of methods of preparation 

 on this have received a great deal of attention during 

 the last three or four years, since it is generally recog- 

 nised that the older stability tests are often unsatis- 

 factory when taken alone. The author has collected 

 and arranged in excellent form all possible inform- 

 ation on this important matter up to quite a recent 

 date. . 



Special reference is made to new patents, and this 

 information will be of great service to those engaged 

 in the manufacture of this important class of bodies. 



J. S. S. B. 



Lehrbuch dcr technischen Physik. By Prof. Hans 

 Lorenz. Zweiter Band, Technische Warmelehre. 

 Pp. ix + 544. (Munchen : R. Oldenbourg, 1904.) 

 The first volume of this text-book, dealing with the 

 mechanics of solids, appeared some three years ago. 

 It was to have been followed by a volume on hydro- 

 mechanics, but this has been delayed to include later 

 developments, and its place has been taken by the 

 present volume on heat, which was originally intended 

 to come third in the series. The general scope of the 

 book is similar to that of the first volume. It is not 

 a " technical " handbook as we understand it. There 

 an- no descriptions or figures of machines, or even of 

 instruments for measurement. There are no details 

 of experimental methods, nor any mention of pie- 

 cautions necessary lor securing accurate results. The 

 whole work is as purely theoretical as any Cambridge 

 mathematical text-book; but the theory is limited to 

 such parts of the subject as have practical applica- 

 tions, with a few numerical tables introduced here and 

 there for the comparison of the equations with experi- 



NO. 1894, VOL. 73] 



mental results. Such a book might be written by 

 anyone of sufficient mathematical ability without any 

 practical knowledge of the subject, and might be 

 thoroughly assimilated by the student without impart- 

 iivT to him any power of applying the theory to a 

 practical case. One cannot help feeling that, in a 

 subject where so much depends on experiment, and 

 for the technical student who wishes to learn how to 

 apply his knowledge, the utility of the book would be 

 greatly enhanced by a judicious admixture of practice 

 with the theory. 



From the purely theoretical standpoint there are 

 many details which are open to criticism. Empirical 

 and theoretical formula? are in places so interwoven 

 that the student would find it very difficult to dis- 

 entangle the theory from the consequences of some 

 purely empirical assumption. Though one would 

 certainly hesitate to recommend the book to the 

 technical student wishing to learn how to apply the 

 theory, it might provide him with a useful kind of 

 mental discipline, and prove a good antidote to the 

 more common kind of technical treatise in which ex- 

 perimental, results are reduced to a series of purely 

 empirical and often theoretically inconsistent formula?. 



11. L. C. 



The Making of East Yorkshire : a Chapter in Local 



Geography. By T. Sheppard. Pp. x+20; 4 plates. 



(London: Brown and Son, 1906.) Price is. 

 The teachers of Yorkshire are blessed by nature with 

 .111 environment of abounding interest; added to this 

 they have, what is equally to their advantage, a 

 goodly supply of able exponents of nature's beauties, 

 amongsl whom the author of this brochure takes a 

 worthy place. 



Mr. Sheppard gives a clear account of the geo- 

 logical vicissitudes through which east Yorkshire has 

 passed from Liassic to recent times. He has naturally 

 ii lei I'd the salient points, but a word or two about 

 the conditions which governed the deposition of some 

 of the argillaceous deposits would have resulted in a 

 better balanced story. The imaginative reader who 

 attempts to visualise the statement at the foot of p. 20 

 will be presented with an awesome and none too 

 truthful picture — but this is quite a small matter. 



Every teacher in east Yorkshire should possess a 

 copy of the pamphlet ; and it would be an excellent 

 thing if our other counties could each be supplied 

 with a similar sketch of their geological history. 



J. A. H. 



Jahrbuch dcr Chemie. Edited by Richard Meyer. 



Pp. \n + 58g. (Brunswick: Vieweg und Sohn, 



1905.) Price 16s. 

 We have previously had occasion to commend Meyer's 

 " Jahrbuch " to English readers, and the new volume 

 compares favourably with its predecessors. 



That lucidity in some of the abstracts is sacrificed 

 to brevity naturally follows from the vast amount of 

 information which is compressed into a limited space; 

 after all, one valuable feature of a year-book is the 

 completeness of its references. It has been previously 

 observed that the "Jahrbuch" has a distinctly 

 German bias, which, perhaps, cannot be entirely re- 

 pressed, but scarcely excuses the omission in the pre- 

 sent volume of references to certain foreign memoirs 

 of the first importance. 



An apology for its late appearance accompanies the 

 volume, and' we are led to infer that the delay may 

 have been occasioned in some measure by the regret- 

 table loss of Dr. Bodlander from the staff of con- 

 tributors, whose place, it may be added, on the section 

 of physical chemistry is now taken bv Dr. A. Coehn. 



J. B. C. 



