158 Notices respecting New Books. 



a limited area of which pressure is applied *. The loaded 

 area may be of any size, and the load need not be uniformly 

 distributed. This elastic problem seemed to me more analo- 

 gous to the case of deposition over a sea-basin than the elastic 

 problem which I supposed Dr. Stoney to be making the 

 corner-stone of his calculations. 



In conclusion, I hope that every intelligent reader will 

 recognize that I have expressed no opinion as to what the 

 earth's physical constitution actually is, or as to the real con- 

 sequences of surface-pressures prolonged throughout geological 

 eras. 0. Chkee. 



June 6, 1899. 



XIV. Notices respecting New Books. 

 Mathematical and Physical Tables. By James P. Wrapsoit, B.A. 



and W. W. Haldane GtEb, B.Sc. London : Macinillan, 1898. 

 TTHIS work is intended as a reference volume for students in tech- 

 -*- nical schools and colleges, and its contents have been chosen 

 to suit the needs of such students. Logarithmic tables and formulae 

 in mensuration and trigonometry naturally occupy a prominent 

 place in the book, and useful expressions in connexion with the 

 analytical geometry of the straight line and conic sections are 

 collected together. We are glad to find that a serviceable list of 

 fundamental integrals has been included, although it might have 

 been followed with advantage by a table of solutions of such 

 differential equations as are of frequent occurrence in physics. 

 Mechanics is represented by a very complete set of formulas, both 

 in dynamics and hydrostatics. In some cases the meanings of the 

 symbols are rather obscure : for example, in the formulae for the 

 various pendulums it is not definitely stated that an oscillation 

 means a single end-to-end swing and not a complete vibration; 

 and in the case of the torsional pendulum the same range of 

 swing is called a vibration. Later on, among the formulas of 

 harmonic motion, the authors have been still more unfortunate ; 

 their definition of period is not the usual one, and does not agree 

 with the equations which follow it. We have chosen these cases 

 because they are just those in which the average student would be 

 most likely to get confused and refer to his book for assistance. 

 The tables in general physics will be found useful ; but that of the 

 composition of air requires revisal, if only to admit the insertion 

 of argon. In the table of units and dimensions we meet with a 

 repetition of the fallacy that the same quantity can have different 

 dimensions in different systems : is the time not yet come when k 

 and p. can take their proper places in these equations '? In a book 

 of this kind there is much material for criticism, and it must not 

 be supposed that the defects pointed out detract seriously from its 

 usefulness to a student of physics or engineering. J. L. H. 



* For examples, see Todlmnter & Pearson's 'History of Elasticity," 

 vol. ii. part ii. pp. 249-256. 



