130 SECTIONAL ADDRESSES. 



of nations. The nation which organises its industry most efficiently, 

 which hampers it least and stimulates it most by legislation, or absence 

 of legislation, and by its scientific foresight, is the nation which will prosper 

 most. Since invention is the heart of industry, the enquirer naturally 

 asks : Is this country doing its best to stimulate invention as a means to 

 foster industry ? Are the leaders of industry fully alive to the position 

 which invention plays in industrial progress ? Have our legislators ever 

 paused to think that their function is only called for because of the progress 

 which has been made by scientific invention, and that without such pro- 

 gress they would be unnecessary ; also that in the past legislation has done 

 much to retard progress ? A study of the fundamental scientific causes 

 of progress would form a useful addition to the education of legislators. 



Invention as a Link between Exact Sciences. 



It is sometimes stated that the Physics of to-day become the Engineer- 

 ing of to-morrow. This is a natural development, since the engineer is 

 more concerned than the physicist with the practical application of physical 

 discoveries. But the converse is frequently true, for many physical dis- 

 coveries and inventions arise in difficulties encountered by the engineer. The 

 science of practical hydrodynamics is a case in point. The mathematical 

 science of hydrodynamics has been of little service to the engineer in the 

 practical problems of the propulsion of ships, in the complex phenomena 

 of vortex motion associated with the flow of water and steam through 

 turbines, or in problems of aerodynamics, with the result that the engineer 

 has had to develop an empirical science of hydrodynamics to supply his 

 immediate needs. A huge mass of experimental results in screw pro- 

 pulsion, in aerodynamics and in hydraulics has thus been accumulated 

 and is now awaiting some discovery or discoveries in mathematics or 

 physics to correlate it all. If vortices could only be dealt with like potatoes 

 or any other form of merchandise, each a complicated physical system in 

 itself but capable of being considered as a unit differing only in mass or in 

 its energy contents, a forward step might be made. The Lanchester- 

 Prandtl theory of lift and drift of aeroplanes is a first step in a particular 

 case of the general problem. Such a discovery, when made, will be bound 

 to lead to further advances and improvements on the engineering side of 

 the subject. 



Most discoveries in Physics arise from some experimental fact dis- 

 covered more or less accidentally. The discovery of Rontgen rays was 

 accidental, and the enormous strides which have been made in our know- 

 ledge of the atom by J. J. Thomson, Rutherford, Bragg, Born and many 

 other physicists during the last thirty years have resulted from Rontgen's 

 discovery combined with another great discovery in pure thermodynamics, 

 Planck's Quantum Theory, which also arose from an accidental discovery 

 made in the course of experiment. The Reichsanstalt in Berlin had 

 published a family of curves representing the distribution of energy in the 

 spectrum of a hot black body. Professor Wien by trial and error obtained 

 an equation to the family, and the form of this equation was suggestive. 

 Planck in trying to develop this equation from the laws of thermodynamics 

 found that he could only do so by assuming that energy is not indefinitely 

 divisible, and he coined the term ' Quantum ' to represent the fundamental 



