A. — MATHEMATICS AND PHYSICS. 49 



structure for the populace to admire, until in the course of time someone 

 takes away a corner-stone and the edifice comes toppling down. It 

 should be like an engine with movable parts. We need not fix the 

 position of any one lever; that is to be adjusted from time to time as 

 the latest observations indicate. The aim of the theorist is to know 

 the train of wheels which the lever sets in motion — that binding of the 

 parts which is the soul of the engine. 



In ancient days two aviators procured to themselves wings. 

 Daedalus flew safely through the middle air across the sea, and was duly 

 honoured on his landing. Young Icarus soared upwards towards the 

 Sun till the wax melted which bound his wings, and his flight ended 

 in fiasco. In weighing their achievements perhaps there is something 

 to be said for Icarus. The classic authorities tell us that he was only 

 ' doing a stunt, ' but I prefer to think of him as the man who certainly 

 brought to light a constructional defect in the flying-machines of his 

 day. So too in science. Cautious Daedalus will apply his theories 

 where he feels most confident they will safely go ; but by his excess of 

 caution their hidden weaknesses cannot be brought to light. Icarus 

 will strain his theories to the breaking-point till the weak joints gape. 

 For a spectacular stunt? Perhaps partly; he is often very human. 

 But if he is not yet destined to reach the Sun and solve for all time the 

 i-id'dle of its constitution, yet he may hope to learn from his journey 

 some hints to build a better machine. 



1920 



