August i8, 192 i] 



NATURE 



777 



Nuova Navigazione Astronomica: Le Rette di 

 Posizione. Teoria — Applicazioni — Tavole. By 

 Prof. G. Pes. Seconda edizione. Pp. lxxxiii + 

 127. (Geneva: Regio Istituto Sordomuti, 1921.) 



The position-line method in navigation was first 

 introduced by Capt. Sumner ; it has greatly grown 

 in favour, since it exhibits in a convenient manner 

 all the information that a single observation of 

 altitude is capable of affording. There have been 

 a large number of nautical tables published with 

 the idea of simplifying the apphcation of the 

 method to determine the position-line of the ship. 

 The "Altitude Tables" of the Rev. F. Ball give 

 the altitude for every degree of latitude, declina- 

 tion, and hour-angle. Other tables by Aquino are 

 in wide use in America. Mr. Herbert Bell pro- 

 posed some useful modifications of the plan of the 

 latter in a paper in M.N.R.A.S., vol. Ixxx,, p. 72. 

 The tables of Prof. Pes are of a different form ; 

 the principal table is one of haversines [i.e. half 

 versed sines), both the natural and logarithmic 

 values being given to five decimals. The author 

 assumes a point on the earth's surface near the 

 estimated position of the ship, and calculates the 

 hour-angle P, and the meridian zenith distance 

 Zm of the observed body, the declination of which 

 is 5. He finds an auxiliary angle 6 from the 

 formula (<^ is the latitude of the assumed point) 



Then 



hav 6= cos <f) cos 5 hav P. 

 hav zen. dist. = hav 6 + hav z. 



A set of four small tables with easily derived 

 arguments enables the direction of the position- 

 line to be determined. 



The ship lies on a parallel line separated from 

 the former by the difference between the observed 

 and computed zenith distances. 



Opinions will differ as to the relative merits of 

 these rival methods of reduction, but at least it 

 may be said that the method given in this volume 

 is sound and fairly short. A. C. D. C. 



A Textbook of Botany for Medical and Phar- 

 maceutical Students. By Prof. J. Small. Pp. 

 x-f68i. (London: J. and A. Churchill, 1921.) 

 255. net. 



There has been little attempt at selection in this 

 book, with the result that a great deal of material 

 has been brought together, some of which the 

 beginner will scarcely be able to use. Nevertheless 

 the book is written with independent views, and 

 will doubtless be of service to many. The illus- 

 trations are a prominent feature, but some of them 

 are on too small a scale to be satisfactory ; e.g. 

 Fig. 67, the legend of which also contains in- 

 accuracies, as well as the figure itself. Such 

 figures as 330 and 913 leave much to be desired. 

 The work touches on every phase of botany, with 

 frequent reference to economic applications. The 

 advisability of including in an elementary text-book 

 such a highly speculative subject as the author's 

 theory of geotropism is very questionable, 

 especially since the statolith theory has received 



NO. 2703, VOL. 107] 



strong experimental confirmation from the work 

 of Bose. In the chapter on heredity it is a mixing 

 of conceptions to apply the term reduplication to 

 the crossing-over of chromosomes. This book 

 will probably find its greatest use as a work of 

 reference for pharmaceutical students and as an 

 accessory text for others. Notwithstanding the 

 above criticisms, it is a welcome addition to 

 botanical text-books. 



Stella Maitland; or, Love and the Stars. By H. P. 

 Hawkins. Pp. viii + 249. (London: Simpkin, 

 Marshall, Hamilton, Kent, and Co., Ltd., n.d.) 

 65. net. 



In a foreword the writer intimates that her object 

 is "to create a deeper interest in the fascinating 

 subject of astronomy, under the conviction that, 

 if once aroused, it can never fail to yield one of 

 the greatest delights which it is possible for the 

 human soul to experience." The aim is commend- 

 able enough, but whether it will be promoted by 

 this rather crude mixture of science and romance 

 must be a matter of opinion. There is no 

 subtlety in the characterisation, and the powder 

 is administered baldly in the form of star-lessons. 

 M. Camille Flammarion's "Stella" appears far 

 more successful, considered as a work of art. But 

 it is a genre in which success is scarcely to be 

 expected. It suffers from all the handicap of the 

 novel with a purpose in its most acute form, and 

 it can make an appeal only to minds of an un- 

 sophisticated type. 



Vocational Chemistry: For Students of Agricul- 

 ture and Home Economics. By Prof. J. J. 

 Willaman. (Farm Life Text Series.) Pp. ix-H 

 294. (Philadelphia and London : J. B. Lippin- 

 cott Co., 192 1.) 8s. 6d. net. 

 Boys and girls in American agricultural high 

 schools are the readers for whom this book is 

 intended. The first part is devoted to the funda- 

 mental facts and principles of chemistry, whilst 

 the second deals with the main chemical facts 

 concerning plant and animal growth, cooking and 

 cleaning, and with milk and its products. The 

 early portion of the book is superficial, and not 

 free from inaccuracies and ambiguities. There 

 are many illustrations, some of which are rather 

 trivial — e.g. "an open fire-place," "a herd of beef 

 cattle " — and some are on pages far removed 

 from the description in the text, no references 

 being given. 



The Moral and Social Significance of the Con- 

 ception of Personality. By the late A. G. 

 Heath. Pp. viii-i-159. (Oxford: At the 

 Clarendon Press, 1921.) 75. 6d. net. 



This essay was awarded the Green moral philo- 

 sophy prize in 1914. The author fell in the 

 war. The book is now published by his friends 

 with the desire, we can well understand, to raise 

 to a comrade a monumentum aere perennius. It 

 shows wide reading and clear thinking, if it pos- 

 sesses no striking originality. 



