478 PROCEEDINGS OF THE AMERICAN ACADEMY 



The selection of a representative was left to the officers of 

 the Academy. 



The death of Arnold Guyot, of Princeton, N, J., Associate 

 Fellow, was announced. 



The special business assigned for this meeting was the pre- 

 sentation of the Rumford medals, which had been awarded at 

 the annual meeting, in accordance with the recommendation 

 of the Rumford Committee. 



The President made the following address in presenting 

 the medals to Professor Rowland : — 



The medals awarded to Professor Rowland have been struck at the 

 Philadelphia Mint, and appropriately engraved under the direction of 

 the Rumford Committee. Their deHvery to the recipient has been 

 postponed for several meetings, under the hope and expectation that 

 Professor Rowland would find it convenient to be present, and receive 

 the medals in person. His attendance with us now is warmly wel- 

 comed, and adds greatly to the interest of the occasion. I ask your 

 kind attention to a brief statement of so much of the scientific work 

 of Professor Rowland as justifies the award of the Rumford premium, 

 and of the relation in which these researches stand to the present 

 condition and needs of physical science. 



Astronomy, at least that part of it which relates to celestial me- 

 chanics, has presented for many generations unchallenged claims to a 

 precision not attainable in any other science. The comparative sim- 

 plicity of its problems, involving only the familiar and measurable 

 units of mass, space, and time, has enabled it to attain and to hold 

 this distinguished position, in spite of the fact that all the senses 

 except vision are excluded from its study. If it has received any 

 assistance from the experimental laws of mechanics, much more have 

 these laws been illuminated by the motion of the planets, where 

 friction and other resistances do not interfere. 



After Grove, in 1842-43, had published his lectures on the corre- 

 lation of the various physical forces ; after Mayer, Ilelmholtz, and 

 others had published their conclusions (the deductions partly of 

 theory and partly of experiment) that these different forces were 

 mutually convertible ; and after the view first seized in prophetic 

 vision by Bacon, Locke, and Winthrop was experimentally estab- 

 lished by Rumford, Davy, Joule, and numerous coadjutors, and with 

 ever-increasing clearness, that the assumed caloric was imaginary, 

 and that heat was only one kind of motion in ordinary matter, — 



