[ 561 ] 



LXVI. Notices respecting New Books. 



A Course of Experiments in Physical Measurement. — Part IV. 

 Appendix for the Use of Teachers. By Harold Whiting, Ph.D. 

 Boston, U.S.A. D. C. Heath and Co. 1891. 

 T\TITH the present volume Dr. Whiting's treatise on Practical 

 ' * Physics is brought to a conclusion. He discusses in it those 

 portions of the subject which are primarily of more importance to 

 the teacher than to the student, such as the cost of providing 

 apparatus for the course described in the three previous volumes, 

 and also the most suitable arrangement of tables in the laboratory 

 in order that the teaching may be imparted with the maximum of 

 convenience both to teacher and student. The author recommends 

 that the practical work be preceded by a special lecture on the 

 theory and practice of the experiment to be performed, these 

 demonstrations being quite distinct from the ordinary formal 

 course of lectures on Physics. It is an open question, and one 

 which the author does 'not discuss, whether the experimental 

 demonstrations ought to precede or follow the formal course ; in 

 the case of the more mathematical portions of Physics it seems to 

 us advisable to interest the student by means of an experiment, 

 before introducing him to the complete theory of it as given in the 

 lecture course. This is especially the case with Mechanics, in 

 which subject the formal lectures ought to follow the demonstra- 

 tions and experiments rather than precede them. 



A great portion of the volume is devoted to tables of actual 

 observations and results obtained in each of the experiments pre- 

 viously described. Then follow lists of the experiments, a know- 

 ledge of which is required in the case of candidates for admission 

 to Harvard University ; this section is of course of greater interest 

 to American teachers. The remainder of the volume is taken up 

 by proofs of the mathematical formulae used in the earlier part of 

 the work. 



In reviewing the treatise as a whole we think the author has 

 done well to insist upon the necessity of always making mea- 

 surements, whatever their nature may be, as exactly as possible, 

 and of eliminating errors by taking the mean of several observa- 

 tions ; so that with comparatively rough apparatus really valuable 

 results may be obtained by a careful student. On the other hand, 

 the work has one drawback which it shares in common with all 

 text-books on practical Physics, namely, that the experiments de- 

 scribed are supposed to be performed with apparatus of a special 

 pattern, which other laboratories do not possess. To a large 

 extent, therefore, the course of experiments in each laboratory is 

 arranged in accordance with the form of the apparatus possessed 

 by it, and such text-books as the present one only serve as general 

 guides which must be supplemented by printed or manuscript 

 notes. James L. Howaed. 



Phil. Mag. S. 5. Vol. 32. No. 199. Dec. 1891. 2 P 



