March ;, 1918] 



XATURE 



The second volume, however, is not on the same 

 plane as the first. It is more ambitious, and aims 

 at the inclusion of much that cannot by any stretch 

 of imagination be considered applicable to the 

 "common telescopes" for which the work was 

 originally planned. The index still fails to reach 

 Mr. Lewis's ideal, though that of the southern 

 sky, thanks to Mr. Innes, is much more complete. 

 Even in the first volume there is much to be found 

 quite admirable in its advance upon the earlier 

 edition. The out-of-date charts of Mars and the 

 moon are replaced by the excellent drawings of 

 • Antoniadi and Goodacre, but the valuable addi- 

 tional notes on the lunar formations, instead of 

 being incorporated with the body of this section, 

 which is one of the best in the book, are put separ- 



(ly in an appendix. 



The increasing size of instruments in the hands 

 of amateurs, which provides the excuse for the 

 ■expansion of the second volume, naturally accounts 

 for the insertion of a section dealing with the 

 micrometer, and Mr. Franks has given a fairly 

 ■complete account of it. But we must take excep- 

 tion to a remark of his on the moving wire. It 

 may happen that bad clock driving by confining 

 one hand to the slow-motion rod may compel the 

 observer to treat one of his moving wires as fixed. 

 But surely we need not accept Mr. Franks's opinion 

 that this is the best method in all cases. 



There are some obvious misprints (c^. nuTjula? 



r nebulae, and Melothe for Melotte), but we select 

 ■^ an example of a blemish in the original work 

 uncorrected by footnote or otherwise the extrava- 

 gant language on p. 233, where we find once 

 more the expressions "inconceivable velocity" 

 and " one of the greatest marvels of the universe " 

 applied to the simple effect of perspective as the 

 comet of 1843 passed from one side of the sun 

 to the other as viewed from the earth. 



W. W. B. 



OUR BOOK§HELF. 



k'<lu/rt Logarithmic and other Tables. By Dr. W. 

 Cawthorne Unwin. Sixth edition, 43 pp. 

 (London : E. and F. X. Spon, Ltd., 1917.) Price 

 |ri5. 6d. net. 

 piESE tables were compiled by Prof. Unwin to 

 acilitate arithmetical calculations in cases where 

 great accuracy is unnecessary, and are selected 

 and so arranged as to be specially useful in the 

 solution of engineering problems. That the book 

 lias been of service to many engineers is evident 

 From the fact that it has reached its sixth edition. 

 The first table gives five-figure logarithms (by 

 use of proportional parts) of numbers up to 9999, 

 and occupies four pages, being followed by anti- 

 logarithms. Trigonometrical tables for the 

 natural functions of angles and their logarithm^ 

 are given for intervals of one minute. Several 

 tables follow, which are adapted for simplifying 

 t ngineering calculations, such as squares, cubes, 

 iuarc roots, cube roots, hyperbolic logarithms, 

 < ight of fall to produce a given velocity, and 

 velocity due to falling from a given height. There 

 NO. 2523, VOL. lOl] 



are also included tables of areas and circumfer- 

 ences of circles, and a segment table, as well as 

 tables of weights of engineering materials.. In ad- 

 dition, the book contains a large number of factors 

 for conversion from the British to the metrii 

 system, and vice versa. The usefulness of a set ut 

 mathematical tables depends very greatly upon thi 

 facility with which the information required can 

 be obtained, and the arrangement of the present 

 set leaves little to be desired in this respect. 

 Health in Camp. By Dr. A. T. Nankivell. 

 Pp. ix + 84. (The Chadwick Library.) (Lon- 

 don: Constable and Co., Ltd., 1917.) Price 

 IS. net. 

 This little book is an amplification of a series of 

 Chadwick Trust Lectures delivered by the author 

 three years ago. It gives in simple language 

 which can be understood by the veriest tyro an 

 outline of camp sanitation and how to ensure 

 health in camp. The author throughout em- 

 phasises the use of the simplest materials and 

 those which are to hand. For example, a grease 

 trap at a washing place may be constructed as 

 follows : A large biscuit tin or oil-drum without 

 a top has a few holes pierced at the bottom. The 

 tin is then filled with heather, gorse, bracken, or 

 wood shavings, and the soapy water is poured 

 in at the top. The water passes through into an 

 earth drain, leaving the fat behind. The bracken, 

 heather, etc., are removed twice a day and burnt 

 in the camp incinerator. 



The empty food tins and incinerator ashes of 

 the camp may be utilised for path-making, and 

 bully-beef or biscuit tins may be built up one 

 upon another so as to make a firm and well-acting 

 incinerator. Final chapters deal with insect pests 

 and the minor ailments of camp life, including 

 the important item of the care of the feet. We 

 feel sure that this book will be useful and interest- 

 ing to all those who live a life in camp, whether 

 they be soldiers, boy scouts, or the less preten- 

 tious dwellers in caravans. 



Rustic Sounds and other Studies in Literature and 



Xatural History. By Sir Francis Darwin. Pp. 



231. (London : John Murray, 1917.) Price 6.v. 



r.'et. 

 A VERY real, if somewhat elusive, charm attaches 

 to most well-finished works the creation of which 

 is felt instinctively to have l>een a labour of love. 

 " Ru.stic Sounds and other Studies " possesses this 

 quality in a marked degree, and the essays them- 

 selves suggest the pleasant conversation of a friend 

 who is drawing on the resources of ripened experi- 

 ence, which he desires to share with others. .\ cer- 

 tain note of {personal intimacy seems to run 

 through the whole volume, and even such debat- 

 able matters as the proper aims, means, and ob- 

 jects of education are discussed in such a way that 

 even those who may differ from the author will 

 scarcely seek to quarrel with him. 



It is, however, when touching on those 

 branches of plant physiology which he has him- 

 self so successfully cultivated that Sir Francis 

 Datvvin appears perhaps at his best. The ease 



