THE DISSIPATION OF ENERGY. 701 



times fester for months. Stoats are tough as leather ; though severely 

 nipped by the iron fangs of the gin, struck on the head with the butt 

 of the gun, and seemingly quite lifeless, yet, if thrown on the grass 

 and left, you will often find on returning to the place in a few hours 

 time that the animal is gone. Warned by experiences of this kind, 

 the keeper never picks up a stoat till " settled " with a stick or shot, 

 and never leaves him till he is nailed to the shed. Stoats sometimes 

 emit a disgusting odor when caught in a trap. The keeper has no 

 mercy for such vermin, though he thinks some other of his enemies 

 are even more destructive. Pall Mall Budget. 



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THE DISSIPATION OF ENERGY. 



By GEORGE ILES. 



SCARCELY had the grand truth been well demonstrated, some 

 thirty years ago, that force can neither be created nor annihi- 

 lated, when it served as a basis for one of the boldest theories ever 

 conceived in the history of science. Prof. William Thomson (now 

 Prof. Sir William Thomson) in 1853 first broached the theory of the 

 dissipation of energy, and since that time many other eminent men 

 have enlarged it and speculated upon it. 



The theory points out, in the first place, that different phases of 

 energy are not transformable into one another with equal ease and 

 completeness. Heat is the only form into which any other can be 

 totally converted. When electricity, mechanical motion, or any kind 

 of energy but heat is sought, an unde'sired production of thermal 

 effect is unavoidable in the most favorable conditions for efficient con- 

 version known to science. Therefore, in the catalogue of terrestrial 

 forces heat is continually gaining in amount at the expense of every 

 other mode of motion. 



Further, not only is it impossible, by any known method, to regain 

 from heat more than one-fourth its theoretical value in useful work, 

 but, as the tendency of all heat is ever to become of uniform tempera- 

 ture, by radiation and conduction, the differences of degree wherein 

 its value as a source of other motion solely lies are being continually 

 abolished. The tendency of energy to appear more and more as uni- 

 formly diffused heat is further shown to be true not only on earth but 

 in the heavens. With respect to the solar system, our present informa- 

 tion, it is held, indicates that it is gradually drifting toward an utterly 

 lifeless state. The sun is parting with its stores of force most lavishly, 

 and must, at however distant a period, become as cold as its planets 

 are now. The planets are little by little losing their force of axial 

 rotation from the friction of their tides, which transmute it into heat ; 



