662 SCIENCE PROGRESS 



matics. In the selection of subject-matter and its treatment, he has been 

 guided by his experience as a teacher of Astronomy, so that the book should 

 be found to meet the requirements of students by stimulating thought and 

 ensuring scientific accuracy." A perusal of the book does not confirm these 

 statements. Not only are there many inaccuracies and loose statements, but 

 the style is tortuous and involved. The following extract from the first page 

 may be quoted as an example : 



" One was almost implicitly impelled to follow the path, traced on the 

 sky, by the sun, the moon and the stars, from day to day, one was perforce 

 led to note the position of the horizon, where the earth and the sky appeared 

 to meet and the points in it, — by a reference to terrestrial objects, — where 

 the heavenly bodies appeared and disappeared and appeared again in their 

 sojourn, according to almost an immutable law, — if supremely, most impres- 

 sively inscrutable, as it is even now, in the main." 



The author has a fondness for commas which is very irritating. For 

 example : 



" That being so, as the earth goes round the sun, and the moon, round 

 the earth, it will, sometimes, happen that the moon, coming between the sun 

 and the earth, will cut off the sun's light — partially or wholly." 



English such as this is not conducive to stimulate thought or to ensure 

 accuracy 1 



It is not possible within the limits of a review to draw attention to all the 

 errors noted in reading the book. It will suffice to refer to a few of them. 

 On p. 201 a proof is advanced of the constancy of the sidereal day as an 

 interval of time. The proof is that the interval between the successive 

 passages of the same star across the meridian, as measured by a clock, is 

 always the same ! A little farther on it is admitted that " no clock can always 

 keep correct time." On p. 129 we are told that Venus does not present to 

 the naked eye any appreciable variation in brightness. On p. 144 it is stated 

 that " there is reason to believe that they [comets] are white-hot masses of 

 gas highly attenuated, increasing in brilliance, as they approach the sun, on 

 account of increased velocity." It is also stated that in some few cases the 

 paths of comets are hyperbolas. This is not correct. There is not at present 

 any well-authenticated case of a hyperbolic orbit. But if we were to accept 

 the author's statement, why does " the fact that the paths of comets are conic 

 sections indicate that they belong to the solar system " ? (p. 145). A body with 

 a hyperbolic orbit cannot very well do so. On p. 141 we are told that Jupiter 

 has four satellites and that Saturn has eight. Although the ninth and tenth 

 satellites of Saturn are comparatively recent discoveries, the fifth of the nine 

 satellites of Jupiter was discovered as long ago as 1892, so that the author is 

 somewhat out of date. What information is conveyed by the following 

 extract from p. 141 : " The most striking facts about them [i.e. Mercury and 

 Venus] are their transits across the sun's disc, that of Mars being necessarily 

 less so than that of Venus " ? A transit of Mars would certainly be a striking 

 sight ! On p. 102 the distance of the moon is given as 23,800 miles, and on 

 p. 182 there are two references to Aldeberran [sic). 



Many more examples of errors, misprints, and loose statements might be 

 quoted, but the above will suffice to show that the last claim which can be 

 made for the book is that of accuracy. It is not a book which we can recom- 

 mend. H. S. J. 



METEOROLOGY 



The Rainfall of the British Isles. By M. de Carle S. Salter. [Pp. xiii 4- 

 295, with 80 figures.] (London: University of London Press, 1921. 

 Price Ss. 6d. net.) 



The plan of isolating for study a single meteorological element is one that has 

 great drawbacks, particularly when that element is as intimately connected 



