OF ARTS AND SCIENCES: SEPTEMBER 11, 1866. 135 



Five hundred and seventietli Meeting. 



June 12, 1866. — Adjourned Annual Meeting. 



The President in the chair. 



Professor Lovering communicated an unanimous recommen- 

 dation from the Rumford Committee that the following vote 

 be passed, viz. : — That the Rumford Premium be awarded to 

 Alvan Clark of Cambridge, for his improvements in the manu- 

 facture of refracting telescopes, as exhibited in his method of 

 local correction. 



Professor Lovering described Mr. Clark's methods of testing 

 and polishing lenses, and recounted the grounds of the Com- 

 mittee's recommendation. 



The report was accepted, and on motion of Dr. Jacob Bige- 

 low the vote was unanimously passed. 



Five bundred and seventy-first Meeting. 



September 11, 1866. — Monthly Meeting. 



The President in the chair. 



The President read letters relative to exchanges ; also let- 

 ters from Professor Rankine and M. Faye in acknowledgment 

 of their election into the Academy. 



The President called the attention of the Academy to the 

 recent decease of Professor Henry D. Rogers of Glasgow, of 

 the Associate Fellows, formerly a Resident Fellow ; also of 

 Dr. Reuben D. Mussey and Mr. James Hayward of the Resi- 

 dent Fellows. 



Professor Winlock read the following communication from 

 Professor Daniel Treadwell : — 



The force of every moving body, or that attribute by which a moving 

 body overcomes any resistance oppo^^ed to it, is the product of two 

 factors, namely, mass and velocity. There is an old dispute as to the 

 true value of one of these factors, the velocity ; but it may, I think, be 

 at the present time confidently assumed that the value assigned to it 

 by Leibnitz, namely, its square, is the true value in this case. Taking 



