SCIENCE 



[N. S. Vol. XXVII. No. 679 



him as her own. The fact that his father 

 was professor of mathematics at the Uni- 

 versity of Glasgow, where his elder brother 

 James became a distinguished professor of 

 engineering, tends to show the hereditary 

 nature of his talent. Brought up in the 

 quadrangle of the university, Thomson as 

 a boy must have enjoyed very unusual 

 advantag'cs of training, while he relates 

 that the enthusiasm of J. P. Nichol, author 

 of "The Architecture of the Heavens," 

 first turned him in the direction of physics, 

 while the good advice of the same master, 

 encouraging him to read Fourier 's"Theorie 

 analytique de la Chaleur" bore quick fruit, 

 which was renewed throughout his whole 

 career. Precocious he certainly was, for 

 his first paper, written at the age of seven- 

 teen, was on Fourier's expansion of func- 

 tions in trigonometric series, followed by 

 three others on the flow of heat, all written 

 before he was eighteen. It is impossible 

 to conceive of an American boy of seven- 

 teen to-day writing on such a subject, 

 which still presents many difficulties even 

 for the mature student, and at that time 

 was understood only by the masters. The 

 theory that precocity is a dangerous symp- 

 tom receives a severe blow from Thomson's 

 subsequent career. 



After being educated at Glasgow Univer- 

 sity he went to Cambridge, and joined St. 

 Peter's College, where he distinguished 

 himself by becoming second wrangler in 

 the Mathematical Tripos, and first Smiths 

 Prizeman, a mathematical honor still more 

 coveted, in 1845. On leaving Cambridge 

 Thomson went to Paris, where in the 

 laboratory of the distinguished physicist, 

 Regnault, he had his first introduction to 

 experimental methods of research. At this 

 time he published the second of his papers 

 on the laws of electrostatics, showing the 

 analogy, never before noticed, between the 

 distribution of what Faraday was calling 

 electrical lines of force with the lines of 



flow of heat in a conductor. In this, as in 

 most of his work then and later, we see the 

 great influence that the work of Fourier had 

 iipon him, and the powers which he had ob- 

 tained in the management of that analysis. 

 In the same year he published his original 

 method of spherical images, which has be- 

 come of so great importance in all parts 

 of mathematical physics. 



In 1846, at the age of twenty-two, Thom- 

 son became professor of natural philosophy 

 at Glasg'ow, where he remained fifty-three 

 years, his jubilee being celebrated with 

 great eclat in the presence of illustrious 

 scientists from all over the world in 1896. 

 Besides his powerful contributions to the 

 theory of electricity and magnetism, which 

 continued for many years, a new and no 

 less important subject now began to engross 

 him. The work of Sadi Carnot on the mo- 

 tive power of heat, though published in 

 1826, was but little understood, and be- 

 longed to the days when heat was supposed 

 to be a substance. Ahnost simultaneously, 

 Thomson in England, and Clausius in Ger- 

 many brought out explanations of Carnot 's 

 principle that heat can do work only in 

 falling in temperature, that is in passing 

 from a hotter to a cooler body, each invent- 

 ing a new axiom to take the place of Car- 

 not 's faulty analogy with the fall of water. 

 The statement of this axiom by Clausius is 

 easier to understand, and it led him to the 

 important conception of entropy, but the 

 line of argument of Thomson was no less 

 originaland compelling, and it led him to 

 the idea of dissipation of energy, which 

 amounts to the same thing. It is worthy 

 of notice that when Thomson began to 

 write on the subject of thermodynamics he 

 still believed heat to be a substance, but he 

 soon accepted the results of the reasoning 

 of Helmholtz and the experiments of Joule 

 on the nature of heat as work, or as we 

 now call it, energy. The most important 

 outcome of Thomson's thermodynamical 



