486 



SCIENCE. 



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



"side. America's two leading physicists 

 were each educated in engineering schools, 

 the one at Troy, the other at Annapolis. 



Helmholtz says: 'Action alone gives a 

 man a life worth living, and, therefore, 

 he must aim either at the practical appli- 

 cation of his knowledge or at the extension 

 of the limits of science itself.' 



Here we have, at once, the justification 

 of the engineer and of the investigator— 

 a view which has, I believe, been accepted 

 by many instructors greatly to the ad- 

 vantage of their method. 



Briefly, then, the marked improvements 

 in method have been: (1) The introduc- 

 tion of the energy viewpoint, thus secur- 

 ing unity and simplicity of treatment; (2) 

 the inti-oduetion of the student laboratory, 

 and (3) the introduction of more concrete- 

 ness; this last being a beneficent reflex in- 

 fluence from the engineering side. 



m. MEN. 



Passing now to the men who have been 

 and are teaching physics in America, the 

 word 'progress' raises a difficult and al- 

 most insoluble problem. At any rate, I 

 shall asume that we all agree in putting 

 the main emphasis upon the spirit and 

 ability of the instructor. The fundamen- 

 tal difference between laboratories is, in- 

 deed, after all a difference between men. 

 What they call at Berlin ' die Glanz-periode 

 der exakten Wissenschaf ten ' — the years 

 immediately following the Franco-Prussian 

 war — ^as essentially the product of four 

 or five men, Virchow, du Bois-Reymond, 

 Hofmann, Kirchhoff and Helmholtz. 



I may as well at the outset confess my- 

 self a hero worshiper and say that my re- 

 spect for the university instructors of the 

 preceding generation— some of whom I 

 met during nine years at Princeton, Ber- 

 lin and Baltimore— is so nearly unbounded 

 that I dare not think the talent engaged 

 in teaching physics to-day is, in any im- 



portant respect, superior to that of the 

 recent past. 



When, however, we turn to the average 

 college instructor or to the average high 

 school instructor it becomes patent that 

 the entire situation has changed. Recent 

 developments in physical science and the 

 duplication of instructors have driven men 

 to specialize. As Professor Runge once 

 said to a meeting of astrophysicists at the 

 Yerkes Observatory: 'Nature is becoming 

 more and more disorderly every day!' 

 The young teacher without special train- 

 ing navigates uneasily a stream beset with 

 small craft hailing him for information 

 about the trolley line, about the automatic 

 telephone, about the transformer, about 

 liquid air, about radium. 



The modern instructor in physics— and 

 I dare say the same change has occurred 

 in other sciences— is first of all a man who 

 has shown his ability to widen the borders 

 of human knowledge. Power to investi- 

 gate is becoming more and more a first 

 criterion for his ability to teach. (Shortly 

 it will be a necessary criterion.) In any 

 event he is a man who has an intelligent 

 interest in and an active sympathy with 

 physical research. 



In the second place, he is a man with a 

 keen Greek perception of relative values, 

 a cultivated sense of proportion, always 

 subordinating mere facts to methods, 

 always placing the power of clear thought 

 above any amount of mere knowledge. 



Again he is frank and fearless in the 

 confession of ignorance, but only after he 

 has made every effort to bring this ignor- 

 ance to a minimum. 



The modern instructor does not trifle 

 with atoms, molecules and other hypothet- 

 ical creatures which he has not seen and 

 does not know about. He takes pains to 

 point out the line of demarcation between 

 the known and the unknovra., believing 

 that few things are more instructive for 



