March 2, 191 1] 



NATURE 



the student of generic forms. A coloured geological 

 map of the British Isles is also included. 



We have mentioned the illustrations at the outset, 

 since the greater number are the work of the 

 fiuthor, and he depends much on them in the 

 physiographic portion of the book. Those of glacial 

 phenomena seem especially excellent. May we, how- 

 ever, mildly protest once more at the translation of 

 roches moutonnees as " sheep-back rocks " on 

 p. 103? 



The use of parts of British Ordnance maps to 

 illustrate geographical features is in pleasant keeping 

 with what has been done in recent text-books in 

 America. But we venture to question whether a 

 book of this kind should deal with geological history 

 by means of a summary of stratigraphy as known to 

 us in the British Isles. Would it not seem better to 

 widen the view of the beginner by letting him know 

 something of the great features of life-progress on the 

 earth? The unconformities mentioned on p. 218 have 

 no importance, except for the specialist in western 

 Europe ; nor are the names Lewisian and Torridonian 

 at all comparable in value with those of the other 

 systems classified in the table, which relate nowadays 

 to no one special country. The real interest of the 

 Carboniferous flora is not conveyed by the statements 

 on p. 269 ; nor is the development of flowering plants 

 fairly represented on p. 311, in view of discoveries 

 outside our islands. 



This introspective point of view, which has been 

 impressed on us for fifty years by university curricula, 

 forces the general reader to meet such things as 

 Coniston Limestone, Blae Wyke Beds, Kimeridge 

 Clay, and Lower London Tertiaries, and leaves him 

 i<Tnorant of the Permo-carboniferous ice-age, and of 

 the immensely interesting development of life-forms 

 and existing land-areas throughout Cainozoic times. 



Dr. Dwerryhouse, however, deals excellently with 

 the Pleistocene ice-age, taking here a bold wide 

 survey. As minor criticisms, we do not like the term 

 "Ammonoid" on p. 293, as applied only to forms 

 intermediate between Nautiloids and "the Am- 

 monites." Something seems omitted in the account 

 of the origin of columnar structure on p. 317; the 

 " forces acting at right angles to ah and towards i 

 and towards 2" are just as "equal and opposite" 

 as those differentiated from them by these terms. 

 The whole point seems to lie in their directions. 



It will be seen that this attractive book admirably 

 fulfils its purpose. Any limitations in the last few 

 pages cannot for a moment be ascribed to narrowness 

 of outlook in the author. G. A. J. C. 



OUR BOOK SHELF. 



British Weights and Measures. As Described in the 

 Laws of England from Anglo-Saxon Times. By 

 Col. Sir C. M. Watson, K.C.M.G., C.B. Pp. xii+107. 

 (London : J. Murray, 1910.) Price 2s. 6d. net. 

 This is an account of the history of weights and 

 measures in England from the time of the Anglo- 

 Saxons to the present day. It is meant to be of a 

 popular character, and is written in an attractive 

 manner, but as it includes the results of independent 



NO. 2157, VOL. 86] 



researches by the author, it may be of some interest 

 to archaeologists as well as to the general public. Sir 

 Charles Watson appears to be an opponent of the 

 introduction of the metric system in this country, 

 and his book is in part intended to show that our 

 present system rests on the experience gained by 

 many centuries of legislation, and accordingly should 

 not be abolished hastily in favour of a system of 

 foreign origin and of comparatively recent date. 

 ^ An interesting account is given of the various 

 "pounds" which have been in use in England. The 

 author is of opinion that the term "troy weight" is 

 derived from an old English word " troi," signifying 

 a balance, and that " avoirdupois " was a generic 

 word used with respect to articles of considerable 

 weight relatively to their value, which were some- 

 times weighed by a kind of Danish steelyard, or 

 desemer, known as an "auncel." His identification 

 of the gallon of Edward I. with the wine gallon of 

 Queen Anne is not very convincing. He gives a 

 good account of Gunter's chain, which he considers 

 an excellent example of the kind of improvement 

 that can be made with advantage in a system of 

 weights and measures without introducing a new 

 standard of measurement. 



On the whole, the author is to be congratulated 

 on having produced an eminently readable book on 

 a subject which is often treated tediously. Some of 

 his suggestions for the simplification of the British 

 system given in the concluding chapter are deserving 

 of consideration, but the proposal to abolish apothe- 

 caries' weight would be unlikely to meet with sup- 

 port in the professional circles mainly concerned. 



On p. 24, line 8, "three-quarters of a yard" should 

 apparently read "a yard and a half." 



Newcomb-Engelmann's Populdre Astronomie, Vierte 

 Auflage. In Gemeinschaft mit den Herren Prof. 

 Eberhard, Prof. Ludendorff, Prof. Schwarzchild, 

 herausgegeben von Prof. P. Kempf. Pp. 

 xvi + 772. (Leipzig: W. Engelmann, 191 1.) Price 

 14 marks. 



Practically a generation has passed away since 

 Newcomb's "Popular Astronomy" was first published. 

 Many popular works have appeared since, but they 

 have not supplanted the original work in its entirety, 

 or provided a better model to which continual exten- 

 sions could be added. 



The main intention of the author has been kept in 

 sight in the present edition. He did not cater for the 

 professional investigator or the special student, but he 

 aimed at placing before the general reading public a 

 condensed view of the history, methods, and results 

 of those portions of astronomical research that pos- 

 sessed a popular and philosophic interest. Like the 

 last edition, the present has been entrusted to the staff' 

 of the Potsdam Observatory. This is fitting, since 

 it is precisely in the department of astrophysics— the 

 direction to which the energies of the Potsdam astro- 

 nomers are more specially devoted — that the greatest 

 progress has been made and the greatest need for re- 

 vision exists. But other astronomers have ably co- 

 operated. Prof. Schwarzschild has rewritten the 

 section on the determination of orbits, and revised the 

 chapter on cosmogony. Seeliger supplies the most 

 recent details on the distribution of stars ; Prof. Kobold 

 revises the cometary statistics ; Dr. Schweydar writes 

 on the figure of the earth, and discusses recent hypo- 

 theses concerning its internal constitution. In this 

 section we should have been glad to see more extended 

 references to the work of Hecker. 



Other sections which have been rewritten or ex- 

 tended are those on stellar parallax (Ludendorff), phy- 

 sical constitution of stars (Eberhard), motions of stars 



