August i6, 191 7] 



NATURE 



^«3 



Cornish, Breton — when the Brythons ruled the 

 land in the prehistoric Iron age. Neither the 

 Belgfic nor the Roman conquest left any physical 

 marks on this isolated community, hidden away 

 in the marshes. 



The best way of understanding" their mode of 

 life is by a comparison with that of the inhabitants 

 of other similar settlements. The Worlebury 

 folk, their neighbours, were in the same stage of 

 culture as the Lake-villagers : practised the same 

 arts — spinning, weaving, pottery-making ; grew 

 the same wheat, barley, and beans ; had the same 

 domestic animals, and lived in the same sort of 

 huts, with this difference, that at Worlebury the 

 huts were sunk in the ground,, instead of being 

 supported by artificial foundations in a marsh, 

 and they were protected from attack by massive 

 stone walls, instead of palisades. 



We have said enough to indicate the value of 

 this elaborate survey of an interesting, isolated 

 prehistoric community, on which the Glastonbury 

 Antiquarian Society and the editors. Dr. .A. Bulleid 

 and Mr. St. George Grav, are to be congratulated. 



MECHANICS AND METALLURGY. 

 (i) Gnida Pratica .del Meccanico Moderno. By 



Arturo Massenz. (Manuali Hoepli.) Pp. 



xxiv4-35i. (Milano : Ulrico Hoepli, 1917) 



Price 4.50 lire. 

 (2) Tempera e Cementazipne deW Acciaio. By 



Mario Levi-Malvano. (Manuali Hoepli.) Pp. 



xii-t-261. (Milano: Ulrico Hoepli, 1917-) 



Price 4 lire. 

 (i) nPHE present volume forms one of the excel- 

 -»- lent series of which Messrs. Hoepli have 

 now published some 600, dealing with the arts 

 and sciences. This work is intended chiefly for 

 foremen and for students of technical and in- 

 dustrial schools who are about to start their works 

 career. Brief descriptions are giveii of the 

 various small tools and appliances met with in a 

 modern shop, with particulars of the operations 

 for which they are intended. The text and 

 illustrations are suggestive rather than fully 

 explanatory, though a series of exercises accom- 

 panies each chapter, thus permitting- the student 

 to follow what he reads. Simple mathematics 

 are introduced where necessary to elucidate any 

 particular point. The heat treatment which 

 metals necessarily undergo in the course of work- 

 ing is explained. The book concludes with an 

 exposition of tTie different systems of screw- 

 threads and of the uses of the various machine- 

 tools. 



(2) This volume attempts to give in a small 

 compass a comprehensive account of the harden- 

 ing of steel for industrial purposes. It is a 

 thoroughly up-to-date little manual, being 

 entirely rewritten from an earlier work published 

 by the same firm. The first part of the work is 

 devoted to theoretical metallurgy — the constitu- 

 tion of iron, the iron-carbon system, effects of 

 heat treatment and mechanical treatment on the 

 structure of steels, etc. — and mentions the work 

 that has been done on the subject by the leading 

 NO. 2494, VOL. 99I 



European metallurgists during the last twelve 

 years or so. In the practical part the various 

 operations of hardening and cementation are 

 described, together with the furnaces used, while 

 the methods of temperature measurement — Seger 

 cone, Fery thermocouple and pyrometer, etc. — 

 are touched on. As an introduction to some 

 larger work on the subject this handbook can be 

 warmly recommended to readers who have 

 attained to some fluency in Italian. The book 

 is well illustrated and printed, and in a form 

 convenient for the pocket. E. S. H. 



OUR BOOKSHELF. 



Experimental Building Science. By J. Leask 

 Manson. Pp. vii + 210. (Cambridge: Af the 

 University Press, 191 7.) Price 6s. net. 

 This book is an indication of the more intimate 

 relations which are growing up between pure 

 science and industry, and provides a course of 

 simple experimental work which should be within 

 the reach of students destined to become respon- 

 sible for the manifold operations comprised under 

 the term "building construction." The author 

 explains the fundamental laws of physics and 

 chemistry, and draws upon building materials and 

 the everyday devices employed in buildings for 

 his illustrations of these laws. The underlying 

 principles, as he points out, are necessarily devoid 

 of any novelty, but the practical illustrations are 

 numerous and well chosen. Starting with an 

 explanation of density and of water and air pres- 

 sure exemplified by reference to water supply and 

 drainage problems, the structure of materials is 

 next shortly dealt with, and then the application of 

 force, which section includes some useful spring 

 balance experiments. The phvsical section con- 

 cludes with some account of heat, and the last 

 third of the book is devoted to elementary chemis- 

 try. The diagrammatic figures are very fully 

 "written up," which should help the student. 

 Partly a text-book, partly a laboratory manual 

 also supplied with test questions, the book is cap- 

 able of a wide application, and should prove useful 

 to the enlightened student of building who realises 

 that if he is to maintain his position in later life 

 he must at least know something of the funda- 

 mental laws of natural science as applied to his 

 work. 



Treatise on Hydraulics. By M. Merriman. 

 Tenth edition, revised with the assistance of 

 T. Merriman. Pp. x -i- 565. (New York : John 

 Wiley and Sons, Inc. ; London : Chapman and 

 Hall, Ltd., 1916.) Price 185. 6d. net. 

 Since the first publication of this book in 1889 

 there have been many notable advances in 

 hydraulics. The eighth edition was entirely re- 

 written, the ninth (1911) reset, and the present 

 edition, contains supplementary sections which 

 bring the volume up to date. General principles 

 are treated in the first three .chapters ; the flow 

 through orifices, over weirs, through tubes, pipes, 

 and conduits, together with the flow of rivers, 



