216 Notices respecting New Books. 



thus become much more expensive. There is one argument in favour 

 of this arrangement, viz. that it will enable students to purchase only 

 those parts which they immediately want ; and those, for example, 

 who only want the elementary subjects, need not buy the part on 

 the lunar and jilanetary theories, &c. 



Notwithstanding the typographical beauty of this new edition, 

 there are misprints and errors in the examples which the editor will 

 probably correct in a future edition. The additional examples form, 

 indeed, the chief recommendation of this new edition over the original; 

 but the greatest care ought to be bestowed to ensure the perfect accu- 

 racy of these examples, which otherwise will only serve to confuse 

 and perplex the student, especially if he has no tutor. The few 

 additions to the original text of 'Pratt' are derived chiefly from MSS. 

 which have long been familiar to the Cambridge student. 



Mr. Phear's ' Elementary Mechanics ' is also a good elementary 

 text-book. The examples are numerous, and apparently well chosen. 

 We extract two simjDle ' questions,' one from his ' Mechanics,' and 

 the other fi-om his ' Hydrostatics,' as good specimens of a class of 

 questions which we should be glad to meet with more frequently in 

 examinations and books : — 



"A shopkeeper has a false balance, and thinks to make his cus- 

 tomers' consequent losses and gains balance each other by weighing 

 the goods which he sells alternately in the one scale and in the other; 

 does he succeed?" (Mechanics, p. 107.) 



" Is it advantageous to a buyer of diamonds that the weighing of 

 them should be made when the barometer is high or when it is low, 

 supposing their specific gravity to be less than that of the substance 

 used as the weight.'" (Hydrostatics, p. 39.) , 



The great fault of all Cambridge mathematical books is, that they 

 do not bear sufficiently on practical subjects. Ingenious problems 

 are framed, having no earthly connexion with any practical purpose 

 or application, whilst hundreds of questions might be proposed quite 

 as good in the way of illustrating mathematical principles and cal- 

 culations, and much more useful. Engineers and other practical 

 men would often be led to consult mathematical works, and to study 

 mathematics, if they found what they wanted in such a course ; but 

 unfortunately they find scarcely anything of practical utility to them. 

 Cambridge men have themselves acknowledged this defect in their 

 system, but few have done anything towards correcting it. The 

 following quotation from Whewell's preface to the first part of his 

 'Dynamics' (published in 1832), is just as applicable now as ever : 

 " Analytical as well as geometrical speculations may be unprofitable. 

 The really important applications of mathematics are so numerous, 

 that it is by no means desirable to employ the student's time on 



detached and useless problems There can be no doubt of the 



advantage which students derive from working out the results of 

 these and similar problems as exemplifications of the application of 

 their principles. But those who would really use their mathematical 

 acquirements for the improvement of their fellow-students in this 

 place, may easily find better subjects for their skill. There are at 

 present a number of branches of natural science to which mathema- 



