484 



SCIENCE. 



[N. S. Vol. XIX. No. 482. 



not hope to train the student in habits of 

 precise thinking without demanding of 

 him nearly the best which the apparatus 

 can give. 



With such an undoubted improvement 

 as the advent of the student laboratory, it 

 was inevitable that some enthusiastic ad- 

 mirers should push it too far. In the 

 earlier days mistakes were undoubtedly 

 made in thinking that if once a labora- 

 tory could be established and once the stu- 

 dent gotten into it, his scientific salvation 

 was immediately insured, if not, indeed, 

 already accomplished. 



But now the pendulum has swung back ; 

 the days of 'organ grinding' in the labo- 

 ratory have largely ceased, and I reckon 

 it not least among recent advances in the 

 teaching of physics that the modern in- 

 structor has learned that an undergrad- 

 uate can not be simply turned loose in a 

 laboratory. Much forethought, indeed, is 

 demanded in order that during laboratory 

 hours the instructor may keep quiet and 

 the student keep busy— and keep busy not 

 on any haphazard problem, but keep busy 

 on a series of problems so graded that, by 

 solving them in order up to any point, he 

 has developed the power of intelligently 

 undertaking the next. Carefully planned 

 courses of this kind are to be found in 

 many laboratories, every one of them a 

 powerful aid toward putting a young man 

 into a position where he always 'knows 

 what to do next,' which, as President Jor- 

 dan has admirably remarked, constitutes a 

 liberal education. 



II. IMPROVEMENTS IN METHODS. 



1. Introduction of the Energy Treat- 

 ment. —lie&Ymg now to one side all ques- 

 tions of material outfit, let us consider some 

 improvements of a still more fundamental 

 nature. I refer to those which have been 

 made in the method of teaching. Here it 



is scarcely possible to believe the changes 

 which a single generation has wrought. 



Progress is something to which the 

 Anglo-Saxon takes so kindly that he is apt 

 to forget just what manner of man he was 

 some thirty years ago. 



Perhaps I can most briefly illustrate by 

 reading a few lines from Tait's review of 

 Balfour Stewart's 'Lessons in Elementary 

 Physics.' Stewart, as many of you know, 

 was one of the first men to treat physics as 

 a single subject— to treat heat, light, sound 

 and mechanics from the energy point of 

 view— the view which, twenty years before, 

 had, as we now believe, been thoroughly es- 

 tablished by Joule, Helmholtz and Kelvin. 

 This review was published in Nature De- 

 cember 29, 1870. Here is what Tait says : 

 "This is a bold experiment and decidedly 

 deserves to be a successful one. * * * It is 

 scarcely possible to form a judgment as to 

 the probable success of the present work. 

 It is so utterly unlike anything to which 

 we have been accustomed that we can only 

 say that we never saw such a work in 

 English at least. * * * The reign of in- 

 artifieiality and simplicity must soon be 

 inaugurated and this work will greatly 

 tend to hasten its advent. ' ' 



These are the remarks of an experienced 

 teacher and able investigator concerning a 

 text-book which to-day we all recognize as 

 eminently natural and simple. So familiar 

 are we with the energy treatment that we 

 are apt to forget how recently these ' water- 

 tight compartments' existed in physics as 

 they yet do, according to the gospel of John 

 Perry, in the department of mathematics. 



But, after all, the energy view-point is 

 merely the outcome of the Lagrangian 

 dynamics and Helmholtz 's little tract on 

 the 'Conservation of Energy.' Trow- 

 bridge's 'New Physics,' appearing some 

 twenty years ago, did excellent service in 

 furthering this standpoint. 



The introduction of the energy idea did 



