OF ARTS AND SCIENCES. 417 



" 5. To George H. Corliss, for Improvements in the Steam-engine. 



" 6. To Joseph Harrison, Jr., for his Method of constructing Steam- 

 boilers. 



" 7. To L. M. Rutherford, for Improvements in Astronomical Pho- 

 tography. 



" 8. To John "W. Draper, for his Researches on Radiant Energy. 



" 9. To J. Willard Gibbs, for his Researches in Thermo-dyuamics. 



" The medals which were awarded to Professor J. Willard Gibbs at 

 the last annual meeting of the Academy, have been prepared under the 

 direction of the Rumford Committee, and are now ready for presen- 

 tation. 



" Rumford lived at a time when the machinery of science was largely 

 composed of supernumerary fluids, interpenetrating or superimposed 

 upon ordinary matter. Newton had indeed banished from mechanical 

 astronomy the celebrated vortices of Descartes; but Franklin and 

 others had introduced a fresh supply of hypothetical fluids into the 

 sciences of electricity, magnetism, and heat. Many of us are old enough 

 to have witnessed a great and pregnant revolution in thermotics ; when 

 the theory that heat is a mode of motion supplanted the old view that 

 heat is an impalpable substance, — the caloric, that is, of Rumford's 

 day. Since the establishment of the new view, many anticipations of 

 it, which produced no impression upon science at the time, have been 

 rescued from oblivion. In a lecture read in the chapel of Harvard 

 College, on Nov. 26, 1755, on occasion of the great earthquake which 

 shook New England the week before. Professor John "Winthrop said : 

 ' There seems to be an inexhaustible source of this heat in the attrac- 

 tive powers which Sir Isaac Newton has shown to belong to the par- 

 ticles of matter ; for heat, consisting of a peculiar intestine motion 

 of the parts of bodies, whatever tends to produce this motion in bodies 

 will cause them to grow hot. Now such a motion may be produced by 

 the particles of different bodies rushing together in virtue of their at- 

 tractive powers.' The philosopher Locke held the same view, and 

 expressed it elegantly, thus : ' "What in our sensation is heat, in the 

 object is nothing but motion.' Bacon's definition of heat antedates all 

 this, and is no less explicit. His words are : ' When 1 say of motion 

 that it is the genus of which heat is a species, I would be understood 

 to mean, not that heat generates motion, or that motion generates heat 

 (though both are true in certain cases), but that heat itself, its essence 

 and quiddity, is motion, and nothing else, . . .' 



" But all these preconceived suggestions of the reasoning faculty are, 



