514 PROCEEDINGS OP THE AMERICAN ACADEMY 



of heat as long as the shortest waves of sound, the broadest chasm will 

 still remain open ; for the rapidity of undulation of these longest waves 

 of heat will exceed that of the shortest waves of sound as many times 

 as the velocity of light is greater than the velocity of sound. And we 

 must still ask the question, What use has nature, with her economy 

 of means and her law of continuity, made of those fifty octaves, or 

 thereabouts, which have no employment in heat or sound? 



I have said nothing of the most recent work of Professor Langley 

 on the solar-lunar energy, hoping that he himself may be willing to 

 address you upon that subject. 



To what, now, shall we say that science is indebted for the startling 

 results which I have hastily and imperfectly presented to you ? Is it 

 to the bolometer ? That led to no discoveries in the hands of its first 

 inventor, and remained unknown and useless, with one slight exception, 

 for nearly thirty years. No doubt, Professor Langley improved vastly 

 upon the original delicacy of the bolometer ; but still it was only an 

 instrument of wonderful precision, demanding all the more skill iu him 

 who used it. Therefore, we owe the discoveries which I have at- 

 tempted to describe to the intelligence which was behind the instru- 

 ment ; to the perseverance and courage which were disheartened by 

 no difficulties ; to the originality which Professor Langley displayed in 

 the complex combinations of the most delicate apparatus ; to the enthu- 

 siasm which brought to his aid all the appliances of science and art from 

 the highest sources ; and to the confidence which he inspired in acade- 

 mies and private friends, so that his work might not languish for want 

 of funds. 



And now, Professor Langley, it is my most agreeable duty and 

 privilege to present to you, in the name of the American Academy, 

 and in the presence of these numerous Academicians who are here as- 

 sembled to administer Count Rumford's trust, the gold and the silver 

 medals, which together make the Rumford Premium. Be pleased to 

 accept, with these medals, my hearty congratulations, and the warm 

 felicitations of all the members of this Academy, for the brilliant re^ 

 suits with which your long and patient work on Solar Energy has been 

 crowned. 



Professor Langley, on receiving the medals, raade the fol- 

 lowing reply : — 



Mr. President, — My labors have met with kind recognition be- 

 fore, but with none that has touched me so nearly as the present, which 

 I receive in the city of my birth at the hands of those many of whose 



