February 21, 1S95] 



NATURE 



387 



ihese scales the divisions are so arranged that all the 

 logarithms of the numbers from i to 10,000 can be easily 

 read off, and vice versa. The scales, or tables as they 

 arc called, are published in two qualities. The cheaper 

 are neatly and clearly printed, and on a smaller 

 i scale than the other ; but, on the whole, we recommend 

 I the more expensive sheets, as the numbering is more 

 <;asy to follow (coloured numbers being used), and the 

 di\ isions are more legible on them. 



To understand the method of working the tables is a 

 matter of only a few minutes' attention, and when 

 grasped, either the logarithm of a given number, or the 

 number from a given logarithm, can be read off without 

 the least hesitation. The book of instruc- 

 tions, which IS separate from the tables, 

 contains all that the user of the tables 

 can require. The explanations are full 

 ,->.nd concise, and the worked-out examples 

 will prove an excellent help in acquiring 

 the methods of solution. 



Jn the Guiana Forest. Studies of Nature 

 :i! Relation to the Strugi;le for Life. 

 15y Jaine> Rodway, F.L.b With an In- 

 troduction by Grant Allen. Illustrated. 

 (London : T. Fisher Unwin, 1894.) 



\\ K have read Mr. Rodway's book with 

 .1 good deal of pleasure. Such a subject 

 as the struggle for existence amongst the 

 animals and plants of the Tropics, could 

 not fail to be full of interest when dealt 

 with by an enthusiastic lover of nature. 

 For it is in the Tropics that nature's 

 principal workshops are situated, ai.d no 

 naturalist can afford, nowadays, to 

 neglect that essential element in a liberal 

 biological education — a visit to these 

 regions. There the struggle for life is 

 no longer, as in our .own climates, a cold- 

 blooded process which only a trained 

 eye can follow, but a fiercely active 

 competition for the means of subsistence 

 which is everywhere apparent in every 

 detail of the structure of the individual 

 and of the economy of the species. The 

 "heartless vegetable" amid such sur- 

 roundings seems no longer a reality, but 

 the cold figment of a northern imagi- 

 nation. 



Mr. Rodway describes the vegetation 

 of the forest, the swamp, the sand-reef, 

 and the sea-shore, and each is sketched 

 in vigorous outline. One cannot, how- 

 ever, avoid wishing that the author had 

 been contented to give his impressions of 

 the actual facts, without indulging in 

 metaphysical moralising which is not 

 scieniific, and is not always common 

 sense. Occasionally, too, he gives way 

 to great prolixity, as, for instance, in an 

 «xcursus on the interdependence of 

 animals and plants, which is all very like something we 

 have heard before, only that Mr. Rodway's siory is 

 longer. The author is on dangerous gr lUiid when he 

 ventures to dip inti the philoso(jhy of natural selection, 

 or to deal with problems of variation. 



But notwithstanding these defects, the book is worth 

 reading. It is well illustrated, and contains a large 

 amount of really interesting observation which may 

 Stimulate the general reader, and which will recall many 

 a half forgotten scene to those who have them elves 

 been travellers. The accompanying illustration, for 

 which we are indebted to the publisher, shows a silk 

 cotton-tree crowded with epiph)tes. 



NO. I 32 I, VOT.. 51] 



Lehrbtich der Experimentalphysik. Von A. Wiillner. 



Band i. 5te Aufl. (Leipzig : Teubner, 1895.) 

 Students who wonder when we are to have an 

 English treatise on experimental physics worthy of com- 

 parison with this well known German one (and the 

 French textbooks of Jamin and Violle), will find food 

 for reflection in the fact that thirteen years have elapsed 

 since the last edition of Wiillner (the fourth) was pub- 

 lished. Much the same thing holds good of other 

 German scientific treatises, notwithstanding that pub- 

 lishing firms of repute in the Fatherland do not consider 

 it beneath their dignity to quicken the sale of the rem- 

 nant of an edition by having notices posted up in the 



^^ 



Universities intimating that bond fide students of the 

 subject can secure copies at a reduced price by applica- 

 tion through the University Professor. 



In the present case the interval has been well em- 

 ployed. The first volume has grown to 1000 pages — or 

 150 more than in the fourth edition— and ihe most 

 important researches published up to the end of 1892 

 have been incorporated. In the last edition the article 

 on internal friciion contained simply a discussion of 

 torsional vibrations and logarithmic decrement, followed 

 bya page in which mention was made of the researches of 

 Schmidt and other-, with a statement of the conclusion 

 arrived at, viz. that in such elastic oscillations the 



