OF ARTS AND SCIENCES. 429 



" The Moon's Zodiacal Light." 



"The Sudden Extinction of the Light of a Solar Protu- 

 berance." 



Professor Trowbridge presented, by title, a paper by Mr. 

 B. O. Peirce, Jr., and Mr. Lefavour, " On the Law of the 

 Propagation of Heat in Solid Bodies." 



Seven hundred and sixth Meeting. 



December 12, 1877. — Monthly Meeting. 



The President in the chair. 



Professor Pickering presented a bound volume of his 

 " Researches in Physics," and read a paper on Atmospheric 

 Refraction. He also presented, by title, the following 

 papers : — 



" Supplementary Note on the Theory of the Horizontal 

 Photoheliograph." By Professor William Harkness. 



" On a Method of Comparing Short Standards of Length." 

 By Mr. Leonard Waldo. 



Professor Peirce presented, by title, a paper on Peirce's 

 Criterion for the Rejection of Doubtful Observations. 



Professor C. L. Jackson presented a paper by himself 

 and Mr. A. W. Field on Parachlorbenzylchloride and its 

 Derivatives. 



Seven hundred and seventh Meeting. 



January 9, 1878. — Stated Meeting. 



The President in the chair. 



The chair announced the death of Dr. J. P. Kirtland, of 

 Cleveland, Ohio. 



On the motion of Professor Pickering, it was 



Voted^ To appropriate two hundred dollars ($200} for 

 improvements in the library room. 



The following papers were presented : — 



