1908] on the Scientific Work of Lord Kelvin. 235 



manly sports, rowing in the Peterhouse boat, which had second place 

 on the river, and winning the Colquhoun sculls, then, as now, one of 

 the main objects of athletic ambition. Afterwards he was expert at 

 curling, until a serious accident on the ice stopped the pursuit and 

 left him slightly lame for life. His subsequent yachting and cable- 

 laying experiences have been already referred to. 



The general imj^ression produced, at first sight, by the four 

 volumes containing the collected scientific papers up to 1S60, might 

 well be a somewhat vague notion of desultory, though profound, 

 occupation with the ideas that were afterwards to be welded by more 

 systematic expositors into our modern theoretical knowledge of 

 mechanical and electrical and optical philosophy. At first glance, 

 the exposition in characteristically practical terminology might even 

 suggest that these papers were concerned with the engineering 

 achievements by which he is most widely known, as much as with 

 new theoretical foundations for physical science. Closer attention 

 has compelled the conclusion that the results of his activity in the 

 early period from 1845 to 1856 are perhaps unique in modern 

 scientific annals ; at any rate there can have been few parallels since 

 Newton and Huygens and their great predecessors. It is said that 

 Lagrange qualified his profound admiration for the genius of Newton 

 by the reflection that only once could it be given to a mortal to have 

 a system of the stars to unravel. Somewhat in the same way one 

 might imagine the reflection of a seer of the future, that it can hardly 

 be given again to a man of genius to have, in his first dozen years of 

 creative intellectual activity, the ideas and discoveries of a Carnot, a 

 Faraday, and a Joule, to interpret and develop for mankind. 



His only peer in general physics in those early days, as also later 

 if we exclude his own disciples, was perhaps Helmholtz. They began 

 their careers of investigation al)out the same time, but at first their 

 paths did not lie much together. For in his early years Helmholtz's 

 professional work was that of a physiologist, though in the essay on 

 the ' Conservation of Energy ' he revealed, in 1847, his true bent as a 

 leader in the exploration of the underlying principles connecting the 

 different departments of the fundamental science, general physics. 

 By the time this famous essay came into Thomson's hands, in 1852, 

 he had himself travelled, with Joule's assistance, as far as it reached, 

 if we except some special apphcations ; but much more, he had in 

 fact already dug down, on the inspiration derived from Carnot, far 

 into the true foundations of the doctrine of Energy as available and 

 recognisable to man, evolving from it ideas now familiar, but then of 

 revolutionary significance, as regards l)oth dynamical science and 

 cosmic evolution, of which no one up to that time had any definite 

 notion. The saving virtue of physical or any other genuine science 

 is, that the most essential discoveries of one generation become worked 

 up so as to be obvious and almost axiomatic to the next. The charm 



