JANUARY 19, 1905 J 



NATURE 



271 



re-cast, and a very considerable quantity of new matter 

 has been added in view of the rapid advance which 

 has been made in electrical theory in the last few 

 years. 



In this edition the author has followed several other 

 text-books in laying: stress upon the importance of 

 the electric field as the real seat of the energy of an 

 electric circuit. It should be clearly brought out, how- 

 ever, that part of the energy must flow in the con- 

 ductor, following there, as elsewhere, the direction of 

 the equipotential surfaces ; the forward flow is, how- 

 ever, in the dielectric itself. The figures exhibiting 

 this flow of energy on pp. 34^4, 525, and 528 are very 

 far from satisfactory. It is sufficient to point out that 

 in every ordinary case of steady transfer the lines of 

 force are convex forwards; indeed, if it be borne in 

 mind that in accordance with Poynting's theorem the 

 flow of energy takes place at right angles to the lines 

 of force, there would be energy flowing out from and 

 not into a conductor if the lines were as shown. 



Too much care cannot be exercised in the construc- 

 tion of diagrams. They catch the eye; and just as 

 nothing is better than a good diagram for inculcating 

 truth, nothing can be worse educationally than one 

 that is slipshod. 



This remark applies equally to a figure illustrating 

 the action of the keeper of a magnet on p. 227, where 

 about twice as many lines of " force " are shown in 

 the keeper as are represented in the magnet itself. Is 

 the keeper supposed to be independently magnetised? 



.\gain, on p. 401, if the equipotential lines on the 

 plate exhibiting the Hall effect w^ere really as shown, 

 some of the current would flow over the edges of the 

 conductor. 



This slovenliness is almost wholly confined to the 

 figures. The text is exceedingly lucid and painstaking 

 in the endeavour to give a student a sound knowledge 

 of physics. The large number of worked out examples, 

 which have always been a distinguishing feature of 

 the book, have no doubt contributed largely to the 

 appreciation which it has received, especially from 

 those who are compelled by circumstances to work 

 without a teacher. 

 Life and Energy — Four Addresses. By Walter 



Hibbert. Pp. xiv+ 182. (London; Longmans, 



Green and Co., 1904.) Price 2S. 6d. net. 

 The thesis of these four addresses — originally delivered 

 at the Polytechnic Institute, London — is that life is 

 not matter, is not energy, but an unceasing non- 

 factorial directive control of energy and its transform- 

 ations. " Directive control," i.e. in the same sense 

 in which " temperature " in the case of heat, or 

 " potential " in the case of electricity, controls the 

 direction in which the energy shall flow. " Non- 

 factorial," because while temperature, potential, and 

 the like are factors of energy, life is not a factor. 



Mr. Hibbert puts most of his points clearly, and 

 much of what he says has considerable force. But it 

 is doubtful if the range of ideas within which the book 

 moves is adequate to the problem. The main position 

 is not unassailable, and the deductions from it in re- 

 gard to morals and religion are occasionally fanciful. 



To descend to details, (i) It is difficull to see how 

 Ihe terms factorial and non-factorial describe precisely 

 the difference between the directive control of energy 

 manifested in inorganic and in organic bodies re- 

 spectively. The discussion on p. 50 rather begs the 

 question. (2) In describing God's directive control as 

 being purely non-factorial, in saying (p. 144). " It is 

 not the office of praver to seek any direct disturbance 

 of the course of material nature," but " its office is 

 to secure a renewed faith in non-factorial control," 

 Mr. Hibbert lays himself open to the retort, " Then 

 non-factorial control is no control at all." (3) " Pro- 



NO. 1838, VOL. 71] 



vided that life is a physical entity, it must be either 

 matter or energy " (p. 16). " If it is a form of matter, 

 it must weigh something " (p. 17). But what if it 

 were ether? (4) "The living plant opens out a new 

 path in which physical law can operate " (p. 39) — " it 

 has, in a sense, directed the energy into special 

 channels" (p. 38). But is this a differentia of life? 

 Surely to one acquainted only with other manifest- 

 ations of energy the path opened out by the dynamo is 

 as new- ;is anything can be. 

 Glossary of Geographical and TopograpliicaJ Terms. 



By .'\le.xander Knox, B.A., F.R.G.S. Pp. xl + 432. 



(London : Edward .Stanford, 1904.) Price 155. 

 This work, which is intended as a supplementary 

 volume to Stanford's " Compendijjm of Geography 

 and Travel," is evidently the outcome of a vast amount 

 of industrious research on the part of the author. The 

 amount of labour involved in the collection of some 

 10,000 geographical terms derived from the most 

 diverse languages all over the world can readily be 

 imagined, and "it can only excite our admiration that 

 so much should have been successfully accomplished 

 by a single individual. The book will be a decided 

 boon to readers of works of geography and travel, 

 who, in the absence of deep linguistic attainments, 

 must constantly be puzzled by the terms employed in 

 the place-names of foreign countries. It will also be 

 valuable to the more scientific geographer as supply- 

 ing a useful basis for the complete dictionary of geo- 

 graphical terms, which has long been felt_ to be a 

 desideratum. Mr. Knox's book, useful as it is, can 

 hardlv be said to supply this need, being concerned 

 rather with the general and popular, than with the 

 scientific and technical usage of geographical terms. 

 It was undertaken in the first instance, as the author 

 explains, with a view to elucidate the terms in use in 

 extra-European countries, and this object it certainly 

 fulfils with success. European geographical terms, 

 which naturally include the majority of those with 

 which the scientific geographer is concerned, are less 

 fully dealt with, and we not only miss many such 

 technical terms as " Karst," "Kar," " Horst," 

 " Schrund," " Avm " (to take a few only at random), 

 but we find little attempt made at discrimination 

 between the terms in use for closely allied features, or 

 at the definition of nice shades of meaning, such, e.g.. 

 as are involved in the words " dale " and " dell," both 

 of which are explained merely as a "valley." Many 

 English local terms are missing, and the definition of 

 others is not always quite satisfactory. On the other 

 hand various Spanish topographical terms are carefully 

 explained, and the recent definitions by the Inter- 

 national Commission for the Study of the Sea of the 

 main features of suboceanic relief are correctly given. 



But the special value lies in the fact that the in- 

 formation supplied is just that which is most out of 

 reach of the ordinary reader, terms derived from the 

 languages of Africa,' Asia, and the less known parts 

 of the world generally, being particularly well repre- 

 sented. The introduction includes some useful hints, 

 by Dr. A. H. Keane, on the laws of interchange of 

 letters in various languages. 

 Blackic's Handy Book of Logarithms. Pp. 128. 



(London 1 Blackie and Son, 1904.) Price 2S. 

 Vier- uud fiinfstellige Logarithmentafehi. Pp. 24. 



(Brunswick : F. Vieweg and Son, 1904.) Price o.So 



mark. 

 In order that mathematical tables intended for common 

 use may serve their purpose, it is essential that great 

 attention be paid to the labour-saving arrangements 

 which authors have from time to time introduced, such 

 as the careful grouping of the figures in rows and 

 columns, the use of varied type or of differently 



