KELVIN 189 



fine harvest, proceeds of his inventions, for at his death 

 he was worth 169,000. He did not look upon it as 

 derogatory for a man of science to reap the pecuniary 

 benefit derived from the sale of the inventions of his own 

 brain ; by so doing he was enabled to add considerably 

 to the general store of knowledge. 



Kelvin's theory of the " dissipation of energy " was 

 announced in a paper on "The Secular Cooling of the 

 Earth," in 1852. He argued that the earth was a hot 

 body like the sun ; that it has gradually cooled, is still 

 cooling ; and that ultimately it will become cool to the 

 core : life will then be untenable owing to the lowness 

 of temperature. 



In 1885 he delivered the Bakerian lecture on the 

 " Electro-dynamics of Qualities of Metals," and in it is 

 published for the first time his " electric convention of 

 heat." Papers on mathematical and physical subjects 

 flowed from his pen, and his inventions were not less 

 numerous. Kelvin, like Newton, was a profound natural 

 philosopher, and the higher mathematics were as play- 

 things to his gigantic and fertile brain. 



Among other papers of Kelvin's may be mentioned : 

 "Rigidity of the Earth," "The Mathematical Theory of 

 Elasticity," "The Thermal Effects of Fluids in Motion," 

 "The Determination of a Ship's Place at Sea from 

 Observation of Altitudes," " Approach caused by Vibra- 

 tion," " An Account of Carnot's Theory of the Motive 



