RECORDS OF MEETINGS. 749 



"Concerning Position Isomerism and Heats of Combustion." L. J. 

 Henderson. March, 1907. 



"Temperature of Mars. A Determination of the Solar Heat Re- 

 ceived." P. Lowell. March, 1907. 



" The Transmission of Rontgen Rays through Metallic Sheets." J. 

 M. Adams. April, 1907. 



Reports of progress in their respective researches have been received 

 from Messrs. A. L. Clark, J. A. Dunne, E. B. Frost, G. E. Hale, W. I. 

 Humphreys, L. R. IngersoU, N. A. Kent, F. E. Kester, A. B. Lamb, 

 C. E. Mendenhall, R. S. j\Iinor, H. W. Morse, A. A. Noyes, J. A. 

 Parkhurst, T. W. Richards, F. A. Saunders, C. B. Thwing, J. Trow- 

 bridge, R. W. Wood. 



At its meeting of January 9, 1907, the Committee voted for the first 

 time, and at its meeting of February 13, 1907, for the second time, to 

 recommend to the Academy that the Rumford Premium be awarded to 

 Edward Goodrich Acheson for the Application of Heat in the Electric 

 Furnace to the Industrial Production of Carborundum, Graphite, and 

 other New and Useful Substances. 



Charles R. Cross, Chairman. 



Mays, 1907. 



Professor Cross continued as follows : — . 



Mr. President and Gentlemen of the Academy, — In presenting the 

 claims of i\Ir. Acheson for the Rumford Premium, in view of the char- 

 acter of the work upon which the recommendation of the Committee is 

 based, instead of making an independent statement of my own, I will 

 read a report upon that work which was presented to the Committee 

 by one of its members, than whom there is none more competent to pro- 

 nounce an opinion upon any subject concerning applied electricity. I 

 hardly need to say that I refer to Professor Elihu Thomson. 



The report is as follows : 



" The early experimenters with the carbon arc fi'om voltaic batteries 

 found that the temperature developed transcended that of all other 

 sources of artificial heat, and numerous substances subjected thereto 

 were found to undergo profound changes. It may sufl&ce to quote from 

 Silliman's Physics, a text-book in common use some forty years ago, 

 page .589, paragraph 886 of the edition of 1870, 'Heat of the Voltaic 

 Arch Deflagration ' : ' Where the positive electrode is fashioned into 

 a small crucible of carbon, gold, silver, platinum, mercury, and other 

 substances are speedily fused, deflagrated, or volatilized, with various 

 colored lights. The fusion of platinum (like wax in a candle) before 

 the voltaic arch is significant of its intense heat, and still more, the 



