November 18, 1921] 



SCIENCE 



477 



text. This surely is a side-stepping proce- 

 dure on the part of the physics teacher, be- 

 cause the student's burning need is to be 

 trained in mathematical thinking, and it is 

 absurd to waste time in any descriptive 

 study unless it be with some immediate and 

 attainable analytical end in view. 



To illustrate faults of physics teaching by 

 examples chosen from mechanics is compara- 

 tively easy; but to illustrate by examples 

 chosen from the equally important subject 

 of electricity and magnetism is very difficult. 

 One reason for this difficulty is, of course, 

 evident; but, in my opinion, the chief reason 

 of the difficulty is that the usual presenta- 

 tion of the elements of electricity and mag- 

 netism is so bad as to be beyond the range of 

 intelligible illustration, so bad as to be actu- 

 ally unthinkable! Here is an attempt at an 

 example, and I might attempt a great many 

 as unthinkable as this! Any wheelbarrow 

 pusher may, if he chooses, think that when 

 he stops a wheelbarrow he does not simply 

 stop it, but he imparts to it an " extra velo- 

 city " in a backward direction. No one 

 would quarrel with such a wheelbarrow pusher, 

 much as one might be tempted to poke fun at 

 him. But what of the text-book-writing phys- 

 ics teacher who injects into a many-page 

 discussion of self-induction the essentially 

 useless idea of " extra current," and in a way 

 which, when reduced to wheelbarrow lan- 

 guage, is exactly equivalent to thinking that 

 he thinks that the " extra velocity " to be im- 

 parted to a stopping wheelbarrow is a for- 

 ward velocity! And yet we ask why students 

 dislike physics. 



The above examples of unintelligible half- 

 way mathematics, of fallacious argument, of 

 purposeless formality, of tiresome repetition 

 and of easy side-stepping have been chosen 

 from the subject of mechanics, and the one 

 attempt to illustrate the futilities which or- 

 dinarily pass as the elements of electricity 

 and magnetism has led us back again to me- 

 chanics! Why? Because mechanics is the 

 only branch of physics in which a real begin- 

 ning has been made in the use of precise ideas 

 by common men. 



I know, from experience, that most of our 

 students like physics when the teaching is 

 directed insistently towards the development 

 and use of precise ideas, and I know that the 

 majority of our students can be carried a 

 long way in this difficult but highly profit- 

 able business. 



But the greatest difficulty in the teaching 

 of physics is to persuade the student to study 

 his text book, and in the face of this diffi- 

 culty physics teaching has degenerated into 

 interminable class-room coaching, making our 

 teaching not only very exhausting but also 

 frightfully expensive, and greatly weakening 

 the morale of our students. What are we 

 to do about it? 



President Hadley made a statement in a 

 brief address before the New Haven Conven- 

 tion of this Society in June, which alone 

 would justify the Convention if it could be 

 taken to heart by our teachers. He said that, 

 although at one time, many years ago, books 

 were used too much, at least, too slavishly, 

 they are now used too little; and the most 

 pressing present need in education work is 

 to place more dependence on books. What 

 are we to do about it? 



'No one would wish a student to use a book 

 unless he can be led to use it effectively, and 

 the trouble, in physics, at least, is that our 

 text-books can not be used effectively. I 

 am, of course, familiar with what is usually 

 considered to be an effective use of a physics 

 text in our non-exacting college courses in 

 physics which run largely to appreciation- 

 stuff, but I do not consider such use to be 

 effective, most emphatically I do not. 



I have discussed college physics teaching 

 with a great many men, and when the dis- 

 cussion has turned to the question of the 

 text book I have always been struck by the 

 tendency of those whom I have known to be 

 the best of teachers to point out the contrast 

 between what they say and do in the class- 

 room and what stands in the text-book. 

 Most of our physics teachers seem to think 

 that a text should be a compendium of all 

 the manifold allusions, suggestions, plausi- 

 bilities, comparisons, analogies, cross-refer- 



