HELMHOLTZ. 789 



As a matter of ordinary mechanics, it had long been admitted that 

 no machine could create power, and as a part of that applied was 

 always lost or frittered away in friction the work coming out of a 

 machine must always be less than that put into it. The first great 

 advance had been made by an American, Benjamin Thompson, after- 

 wards Count Eumford, when he asked what became of that part lost 

 in friction and found his answer in the heat generated thereby, thus 

 proving that "heat was a mode of motion" rather than an "imponder- 

 able agent," as it was rather ambiguously designated up to nearly the 

 middle of this century, but that all of the forces of nature were so 

 related to each other as to be interconvertible, and that the sum total 

 of all the energies of the universe was always the same, energy being 

 no more capable of creation or destruction than matter 5 these were 

 great facts, mere glimpses of which had been permitted to the physi- 

 cists of the early part of the century. Helmholtz was certainly one of 

 the first to completely grasp this splendid generalization, and not more 

 than two or three others stand with him in the credit which is due for 

 its complete proof and general acceptance. His first contribution had 

 the merit of being quite original in conception and execution, for he 

 then knew almost nothing of what others had done; he was entirely 

 ignorant of the important paper of his fellow-countryman, Mayer, and 

 knew only a little of Joule's earlier work. The principle of the con- 

 servation of energy, which for a quarter of a century has been the 

 open sesame to every important advance in physical science, was not 

 then, to say the least, a popular topic. But for five or six years 

 a young Englishman named Joule, not yet 30 years old, had been 

 engaged with it and, from the point of view of the engineer, had made 

 it his own. On the 28th of April, 1847, he gave a popular lecture in 

 Manchester, where he lived and died, which was the first full exposi- 

 tion of the theory. A few weeks later Helmholtz read his paper in 

 Berlin. In England, even the local press refused to publish Joule's 

 address, but finally the Manchester Courier, moved by the family influ- 

 ence (the elder Joule being a wealthy brewer), promised to insert the 

 whole as a special favor. In Germany the subject met with only a 

 little more favorable reception, and the leading scientific journal, Pog- 

 gendorff's Annalen, declined to publish Helmholtz's paper. Even at 

 the meeting of the British Association at Oxford a few months after 

 the Manchester address, when Joule again undertook the exposition 

 of his theory and his experimental proofs of it before what ought to 

 have been a more friendly audience, he was advised by the chairman 

 to be brief, and no discussion of his paper was invited. As Joule him- 

 self relates, his presentation of the subject would have again p roved a 

 failure "if a young man had not risen in the section and by his intelli- 

 gent observations created a lively interest in the new theory." This 

 young man was William Thomson, then 23 years old, now Lord Kelvin, 

 the foremost of living physicists. 



The tremendous blows struck by Helmholtz in support of the new 



