ENGINEERING AND PURE SCIENCE — SWANN 215 



as temperatures — as pressures — as elasticity, etc. The advent of elec- 

 tronic physics has brought us down to the properties of the atomic 

 particles themselves. In the photoelectric cell, in the photomultiplier, 

 in the radio vacuum tube, and a dozen similar devices, the matters 

 which determine successful operation are things which can be under- 

 stood only in terms of the fundamental processes of nature or, at any 

 rate, I think it would be safe to say that it is not much more difficult 

 to understand them in these terms than to understand them in terms 

 of some artificial scheme of simplification devised because one has 

 learned to expect simplification in the past and to hope for it in the 

 future. 



And then, as the realms of empiricism in the ordinary properties of 

 matter have become exhausted, the new realms of enlightenment fol- 

 lowing our modern picture of the structure of solids have tempted us 

 to hope that, even here, the barrier of knowledge need not be fixed by 

 the laws of empiricism or, if we like, by an extrapolation of the past, 

 but rather by the possibility of prediction in relation to what we know 

 from the atomic structure of matter itself. 



It is a matter of great importance to understand what governs the 

 strength of materials, what governs the dependence of this strength 

 upon temperature, particularly in the light of modern requirements 

 in high temperature operation such as is encountered in turbines. The 

 atomic picture is very illuminating in this field and can, in many cases, 

 point the way to success, whereas to achieve that success by what we 

 may call the Edisonian method of multitudinous trials would involve 

 untold expenditure of time and effort. We have not reached the stage 

 at which we can design substances of any desired characteristics, but 

 we have reached the stage at which our knowledge of atomic physics 

 provides us with very good hunches as to courses of procedure which 

 have a good chance of being successful. Of course, one of the most 

 spectacular of all such predictions is that involved in the act of man 

 in creating an entirely new element, plutonium, in connection with 

 his work on atomic energy. 



Now, in order to manipulate atomic properties successfully, it is 

 necessary to think in terms of atomic laws, and such laws are rather 

 artificial to the thinking of the conventional metallurgist. However, 

 in the last analysis, they are really no more artificial than the laws 

 with which he has become familiar. It is for the future to season the 

 younger generation with a broader sensitivity to the forms of nature's 

 laws, so that he may not, forever, stay with his feet bound in the mud 

 of classical antiquity of which he has already exhausted most of the 

 good essence. It is necessary to bring him to a stage where he is not 

 limited to looking at the new fields from afar but is enabled to walk 

 in them with confidence, and pluck such good fruit as comes his way. 



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