I 



TRANSACTIONS OF SECTION G. 741 



In the case of a problem in pure mathematics or physics, where only one right 

 solution can exist, that solution is arrived at by the help of a thorough knowledge 

 of the science in question — there is little room for the critical faculty except as to 

 method — the result is either right or wrong. With our work, on the other hand, 

 solutions of all problems except the very simplest — in other words, decisions on all 

 points which present themselves— can be arrived at only by a process of criticism 

 applied to the problems, to their statement, to their condition, to all their many 

 possible solutions. The development of the necessary critical faculty should be 

 one of the chief aims of every teacher and every student. 



A scientihc training cannot make a man an engineer. Perhaps it is impossible 

 for anything to make a man an engineer unless he has grown that way from the 

 beginning! But a scientific training may make him, or at least give him the possi- 

 bility of making himself, a critic. 



In the vigorous attempts which have been made to specialise the education of 

 engineers very early, 1 am afraid that the idea of teaching subjects is sometimes 

 too prominent, to the neglect of matters less obviously useful. It is, of course, one 

 thing to know a subject Irom the examination point of view, and quite another to 

 be able to think about it, and still another to be able to write about it. In parti- 

 cular, I have often regretted to find how little attention has been given to a matter 

 which perhaps may be called literary rather than scientific, but which is all-impor- 

 tant in criticism, I mean to the power of expression. It is not easy to overrate 

 the importance to the engineer, as to other folk, of the power of saying clearly 

 what he means, and of saying just what he means. I do not mean only of doing 

 this for its own sake, but because if a man cannot say or write clearly what he 

 means it is improbable tbat he can think clearly. By the power of expression 

 I do not mean, of course, the mere power of speaking fluently in public, a thing 

 ■which appears physically impossible to some people ; I mean rather the power of 

 expression in writing, which carries with it clearness and consecutiveness of thought. 

 It is difficult to know how this matter can be taught, but at least it can be in- 

 sisted upon probably to a much greater extent than is commonly the case. A 

 man requires to see clearly not only the exact thing which he wants to say, but 

 the whole environment of tbat thing as it appears to him. Not only this, but he 

 must see the whole environment of the same thing as it appears to the persons 

 for whom he is writing, or to whom he is speaking. He has to see what they 

 know about the matter, what they think, and what they think they know, and if 

 he wishes to be really understood has got to do much more than merely write the 

 thing he means. He has carefully to unwrite, if I may use the expression, the 

 various things that other people will be certain to think that he means. For after 

 all the great majority of people are very careless listeners and readers, and it is not 

 for the small minority who are really exact in these matters that one has to v/rite. 

 Moreover, it is a great help to clearness of thought and expression to keep before 

 one always an ide.al audience of people who will certainly misunderstand every single 

 sentence about which any misunderstanding is in any way possible, and some ethers 

 as well. 



In attempting to think out or to discuss any question, whether it be technical or 

 non-technical, in fact, as long only as it is non-political, the first necessity is pro- 

 bably a knowledge of the question itself, and not only this, but also a proper 

 understanding of its whole environment. This knowledge must be of such a kind 

 as to distinguish what parts of it are important, what parts of it are unimportant, 

 what parts can be described in two sentences, and what others may require as 

 many paragraphs ; what parts afl'ect the result but little, however large they seem ; 

 and which ones must be considered vital, although their very existence is difficult 

 to discover. The faculty which enables a man to handle his knowledge in this 

 fashion may be summed up in the single expression ' sense of proportion.' More- 

 over, the knowledge, to be of real value, must be as totally free from prejudices 

 and prepossessions as in the most rigorous branch of pure science, and as thoroughly 

 imbued with a healthy spirit of scepticism. 



One is accustomed to think of engineering work as mainly constructive. But 

 after all it is quite as much critical. In almost every department of mechanical 



