December 28, 1899] 



JSiATURE 



197 



In a list of Egyptian (Naukratite) porcelain charms 

 and ornaments on p. 137, Mr. Myres mentions "4726- 

 4732. Hawk-headed deity with disc on head. . . . 

 4736-4737. Hippopotamus-headed deity. . . . 4746- 

 Ram-headed deity." We are not informed whether 

 4746 is Amen or Khnemu, and the names of 4726-4732 

 (apparently Ra) and 4736-4737 (Taurt) might well have 

 been given. And what is the inscription on the Baby- 

 lonian cylinder, No. 4501, which, by the way, is not 

 necessarily of early date, about ? The " hieroglyphic in- 

 scriptions" on the scarabs (Nos. 4541, 4547-4549; 

 p. 135) are ignored. 



Turning to a comparatively unimportant detail, we note 

 a frequent occurrence of the hideous Germanism, "snow- 

 man technique." Cannot some better term than this be 

 devised for the style of what are merely rude hand-made 

 figures .-* 



The labour of correcting misprints in such a work 

 must have been colossal ; but the result is extremely 

 good. We only notice Ra-men-kepher for Ra-men- 

 kheper on p. 135. To Mr. H. B. Walters, who read the 

 proofs through, much praise is due. He is also re- 

 sponsible for the annexed reports on excavations at 

 Kurion, Salamis and Maroni, from which a good idea of 

 the marvellous mixture which the average Cyprian tomb 

 contains may be obtained. We are still far from 

 being able to dogmatise with regard to Cyprian 

 architology ! 



The indices also deserve praise, but the mistaken aim 

 of making the book serve as a traveller's guide has, by 

 restricting its size, sadly curtailed the number and size of 

 the plates. 



Generally speaking, the book will be to the " way- 

 faring man" (p. viii.) of little use, but to the archaeologist 

 it will no doubt prove valuable. Although, we expect, 

 that if he already knows the collection, he will often find 

 it difficult to recognise the objects from Mr. Myres' and 

 "0-R"'s somewhat meagre descriptions of them, yet the 

 care with which the known provenance of all objects is 

 noted, and vague statements on the subject are sifted and 

 verified by the authors, will be of great assistance to 

 him. He will know how far Mr. Myres' archaeological 

 theories will be of service to him. If archaeology is to 

 be constructive, if it seeks to explain its discoveries, it 

 must formulate hypotheses. These hypotheses are often 

 suggestive, often really explain things in a manner 

 which, as far as we can know, is perfectly satisfactory ; 

 but as often they are mere ballons cTessat, improbable 

 and unsatisfactory. Hypotheses of both kinds occur in 

 the introduction to the Cyprus Museum Catalogue : the 

 archaeologist will be able to distinguish between them, 

 but the " wayfaring man " has no means of separating 

 the wheat from the chaff. On him, therefore, it cannot 

 be too strongly impressed that the whole story of the 

 development of human civilisation in Cyprus and the 

 .^gean basin before the 8th century B.C. is still merely a 

 collection of hypotheses, sometimes agreeing, more often 

 disagreeing, with one another, and therefore that any 

 description of " Early Man " in Greece or in Cyprus 

 is .not a statement of historical facts, but a simple 

 expression of the individual opinion of its author on 

 the subject. 



NO. 1574, VOL. 61] 



TEXT- BOOK ON ^HE STRENGTH OF 



MA TERIALS. 



The Strength of Materials. By Prof. J. A. Ewing, F.R.S. 



Pp. xii 4- 246. (Cambridge University Press, 1899.) 



ALL teachers and students of applied mechanics will 

 heartily welcome this book. It is based on the 

 author's article, " Strength of Materials," which appears 

 in the ninth edition of the Encyclopcedia Britannica. As 

 in his book on the " Steam Engine," the present book 

 is characterised by Prof E wing's excellent style and 

 clearness 0/ exposition. The subject matter includes 

 those portions of the subject which are usually taught 

 at the higher colleges. 



The author wastes no time in plunging into his subject. 

 The first two chapters are devoted to a general analysis 

 between stress and strain, and the relation between the 

 three elastic coefficients in an isotropic body. Probably 

 many teachers would prefer to postpone the considera- 

 tion of part of these two chapters— particularly the con- 

 tents of the second — to a later stage of the book, and 

 this can readily be done without interfering with the 

 usefulness of the book as a text-book. Chapter iii. 

 deals with non-elastic strain, a part of the subject on 

 which Prof Ewing is particularly qualified to speak. A 

 concise account is given of some of the recent experi- 

 ments of Mr. Muir on the effect of heating in facilitating 

 recovery of elasticity after overstraining, and it is to be 

 hoped that in any future editions the author will give a 

 full account of the very recent experiments by Mr. Rosan- 

 hain and himself on the crystalline structure of metals 

 — a subject which, in the present edition, is merely re- 

 ferred to. The fourth chapter will be found exceedingly 

 valuable to the teacher, dealing, as it does, with the test- 

 ing of materials, and containing photographs of several 

 pieces of self-contained apparatus designed (by the 

 author) to determine the various elastic constants, and 

 which have been proved to be serviceable in the author's 

 laboratory at Cambridge. Chapters v. and vi. deal with 

 uniformly-varying distributions of stress, and the bending 

 and shearing stresses induced in beams. On page 98 

 will be found some interesting remarks on the variation 

 of stress over different sections of a tie-rod. In dealing 

 with this subject it is interesting to notice that in a 

 uniformly strained piece of any shape whatever having 

 parallel sides, the distribution of stress over any section 

 might be graphically determined by Prof. Hele-Shaw's 

 method of the flow of a viscous fluid between two 

 parallel plates placed very near together, the boundaries 

 having the same shape as the piece considered. The 

 stress at any point will then be inversely as the dis- 

 tance between adjacent stream-lines, the stream-lines 

 being supposed spaced at equal distances apart at a 

 section where the stress is uniformly distributed. The 

 deflection of beams and the question of continuous 

 girders are discussed in Chapter vii., whilst in Chapter 

 ix. will be found a luminous treatment of struts and 

 columns. Chapter x. is devoted to a consideration of the 

 torsion of shafts and of springs, whilst in Chapter xi. the 

 stresses induced in thin and thick cylinders due to in- 

 ternal or external pressure, and in a thin rotating disc 

 are treated in an exceedingly lucid manner. A valuable 

 addition to the contents of these chapters would be an 



