January. 1911. 



KNOWLEDGE. 



35 



jjeneral folks who love to read about astronomy, should fail 

 to read, better still, acquire, this book. It is a book well 

 suited for municipal and lending libraries, which mainly exist 

 for e.xciting and stimulating a reader's interest in a subject. 



The printing is clear and on light, thick non-surfaced paper ; 

 there are thirty-three chapters, and more than a dozen 

 excellent plates, reproduced from photographs by Max Wolf, 

 Puiseux, Janssen, and Lowell ; there is also a good index. 



B. 



Ball's Popular Guide to the Heavens. — Third and Revised 

 Edition. 96 + xii. pages. 84 maps. 



(George Philip & Son. Price 15 - net.) 



We are glad to see this indispensable volume kept to the 

 fore, by a third edition five years after the second edition. 



In 1892 Sir Robert Ball, greatly aided by the present 

 Radcliffe Observer (Dr. A. A. Rambautl, who formed two- 

 thirds of the seventy-two plates, besides a large portion of the 

 seventy-two pages of letter-press and index, wrote the first 

 edition of this guide, then called An Atlas of Astronomy ; 

 that work consisted of seven chapters of text, which preceded 

 the seventy-two plates. In the second and third editions a 

 small number of these maps, chiefly of planets and comets, 

 have been omitted or superseded by later work, and we find 

 such names as Barnard, Ritchey, Hale, Campbell, Keeler, and 

 so on, supplementing or replacing work by Common, Green, 

 Roberts, Henry, Proctor, and others ; astronomical progress 

 demanded these changes. So that the changes result in a 

 volume of eighty-four maps and ninety-six pages of letter-press 

 in nine chapters. 



The maps which were not included in the first edition, are 

 chiefly those of the nebulae, comets, and sun. .An important 

 change, and an improvement upon the first edition, is in printing 

 the maps of the tracks of the planets and the star maps upon 

 a blue ground. 



The maps are for the most part so excellently reproduced 

 and cover the ground of astronomy so well that it is difficult to 

 know where to find fault. But there are a few faults to which, 

 in view of a fourth edition, we draw attention, as they have 

 already been reprinted from the second edition. On page 13, 

 Saturn's rings "are now (1903)." This is incorrect; the 

 sentence required re-writing; page 17, a misprint for shadow- 

 patch, also wrong in second edition ; page 60 and other pages, 

 deceased astronomers are sometimes referred to as " late," 

 sometimes not ; page 62, we think the number of stars in the 

 Astrographic Survey Catalogues will be nearer four millions 

 of stars than two millions, and the year (1903) is wrong. We 

 also notice on page 54 that the maximum magnitude of Nova 

 Geminorum is given as seven ; it should be five, or even 

 brighter, and an important omission occurs in the list of new- 

 stars, Janson's discovery in Cygnus in 1600; again on page 6. 

 referring to Halley's comet, the author says " and its next 

 return in 1910 will be awaited with very great interest." This 

 was correct for the second edition of 1905 ; it is rather 

 unfortunate that this should not have been corrected in the 

 present edition, knowing that Halley's comet had come and 

 gone five months ago, and that a frontispiece of this comet is 

 given. Considering the many beautiful photographs of the 

 comet which have been taken by Curtis (Lick Observatory), 

 at the Cordoba and other favoured observatories, it is also to 

 be regretted that this comet's beauty should be so depreciated 

 and so unfavourably compared with the January comet by the 

 drawing given. In future editions we would like to see 

 reproduced the binary star information as in the first edition, 

 but in a popular guide possibly that would be out of place ; 

 also a photograph of Halley's comet and some of Hale's 

 beautiful solar work. The distribution of the text among the 

 plates is a step in the right direction, and more appropriate to 

 such works. May this volume reach many more editions and 

 maintain its high character as a book which is needed in the 

 obser\ atory and in the astronomer's library. 



F. A. P.. 



BOTANY. 



.4 Text Hook of Botany.— By J. M. LovvsoN, M.A., B.Sc. 



Fifth Edition, Re\ised and Enlarged, 607 + vii. pages. 



Illustrated. 7-in. X ; -in. 



(W. B. Clive. Price .-5.) 



Although written specially to meet the lequirements of 

 students reading for certain examinations, this work has 

 decided merits, which have led to its being used extensively 

 by botanical students. As a handy and concise compilation, 

 published at a moderate price, it can be recommended to all 

 who wish for a single book to serve for reference, as well as 

 an introduction to more detailed works dealing with the 

 different branches of the subject. 



The present edition differs from its predecessors n^ainly in 

 containing a large amount of m.atter which has been taken 

 from the works of Professor Cavers, published by the same 

 firm. 



Plant hife in .Alpine Sicitzerland. — By E. A. Newell 



Arber, M.A., F.L.S., F.G.S. 355 pages. 48 plates. 



30 figures. 8i-in.X5-in. 



ijohn Murray. Price 7 6 net.) 



The wild flowers of the Alps, so numerous and so brightly 

 coloured, cannot fail to attract the sununer visitor. He 

 gathers them, and finding them very different from the flowers 

 of his own country, seeks to know their names. To aid him 

 in this, there are a thousand books with gaudily coloured 

 pictures, but should he desire to go a step further and find out 

 something of the life histories of these flowers, and why they 

 differ so markedly from the flowers with which he is familiar, 

 there are very few popular books to which he can turn for 

 guidance. 



The volume now before us is in no way a flora, and very 

 little is said as to the identification of the plants described. 

 The introductory chapter deals with points in the structure of 

 two of the best known of .\lpine plants, the Alpenrose and the 

 Edelweiss. Typical flowers of the meadows, pastures, rocks, 

 marshes and forests are next discussed, and their special 

 adaptations to the regions in which they are found, and to one 

 another, are explained. The last chapter is given up to a 

 discussion on the afiinities and origin of the Alpine flora. A 

 glossary of botanical terms, some notes on the structure of 

 the flower and a bibUography form an appendix. 



It has clearly been the object of the author to make the 

 whole book abundantly intelligible, even to those without the 

 slightest botanical knowledge, and in this he has succeeded 

 well. If we must criticise we would almost suggest that in 

 the first chapter the intelligence of the reader is perhaps a 

 little insulted, that even too much water is added to the milk. 

 The book is well illustrated by some excellent diagrams and 

 there are some forty-eight plates, reproduced from photographs, 

 some of which are exceedingly good. There was clearly a 

 definite need for a book of this sort, and we feel that the 

 present volume is admirably adapted to meet it. 



GEOLOGY. 



Smithsonian Miscellaneous Collections. Vol. 56. No. 5. 

 .4 Preliminary Study of Chemical Denudation. — ByF. W. 

 Clarke, Chief Chemist, U.S. Geological Survey. 19 pages. 

 No. 6. The Age of the Earth. — By G. F. Becker. 28 pages. 

 (Smithsonian Institution). 



Dr. Clarke's paper is occupied with a revision of those 

 geochemical data which are used in the discussion of some of 

 the larger theoretical problems of geology. On the basis of 

 the vast amount of material accumulated by the Hydrographical 

 Department of the U.S. Geological Survey, a new estimate is 

 made of the amount of matter carried down by North 

 American rivers in solution to the sea. For the United States 

 the revised denudation factor is seventy-nine metric tons of 

 dissolved matter per square mile of drainage basin per year. 

 Revised estimates are made as far as possible for South 

 .American, European African, and .\sian rivers, but the data 



