Clerk Maxwell 33 



view which gave to the aether the properties of elastic 

 solids. 



Brought up in a school of physicists which based the 

 explanation of natural phenomena on perfectly defined 

 conceptions, and required, therefore, always a mechanical 

 model to represent properties of matter and force, Maxwell 

 in his first efforts tried to outline the mechanical construction 

 of the aether necessary to explain the electrical effects. He 

 conceived this aether, the ultimate elements of which retained 

 the properties of the cruder forms of matter, to be composed 

 of cells, each of which enclosed a gyrostatic nucleus. 

 Gradually, however, he abandoned these attempts at finding 

 a mechanical model for the aether, and was satisfied to rely 

 mainly on the mathematical formulae which expressed its 

 properties in the simplest way. In this he followed, or, to 

 be strictly accurate, helped to initiate, the modern tendency 

 of refusing to go beyond the immediate results of observa- 

 tion, relegating tacitly all questions of interpretation to the 

 domain of metaphysics; which means disregarding them 

 altogether. Maxwell's electrical work has revolutionized the 

 whole aspect of science ; and though undertaken in the purest 

 spirit of philosophic enquiry, it has led directly to the great 

 practical results which we see in the present applications of 

 wireless telegraphy. 



It is seldom that it is given to one man to open out new 

 paths of thought in more than one direction. Newton's 

 theory of gravitation and his optical work is an example 

 of such a rare success, and there is perhaps no other equally 

 marked except that supplied by Maxwell. Though his 

 work on the constitution of gases may not have been as 

 far-reaching in its results as the monumental researches we 

 have already noted, it has introduced a new and original 

 idea into the treatment of the properties of matter. 



Towards the middle of last century, Herapath had 

 revived the theory originally proposed by Daniel Bernoulli, 

 according to which the pressure of a gas is due to the impact 

 of its molecules against the sides of the vessel which contains 

 it, and Joule, adopting this view, had calculated the velocity of 

 the molecules of a gas from its known density and pressure. 

 Such calculations can only give us the measure of an 



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