OF ARTS AND SCIENCES. 373 



presented the following vote on this subject from the Rum- 

 ford Committee : — 



" Voted, That the Academy be requested to appropriate a 

 sura not exceeding five hundred dollars for the purpose of 

 enabling the Rum ford Committee to obtain, by direct com- 

 parison, accurate copies of the revised original standards of 

 the French metre and kilogramme : these copies being con- 

 sidered indispensable for independent researches upon light 

 and heat in this country." 



The following papers were presented : — 



" On the Magnetization and Demagnetization of Iron." 

 By John Trowbridge. 



"Apparatus for Illustrating Periodic Motion." By John 

 Trowbridge. 



Professor Trowbridge presented the following contributions 

 from the 'Physical Laboratory of Harvard College : — 



" Effect of Distance on Appreciation of Color." By W. 

 H. Schwartz. 



" On a Standard for Estimating the Reflection of Light." 

 By A. H. Lea. 



Seven hundred and twenty-seventh Meeting. 



January 14, 1880. — Stated Meeting. 



The President in the chair. 



Mr. Lyman presented a report of progress made by the 

 Centennial Committee. 



Professor Cooke called attention to the first part of Volume 

 XV. of the Proceedings, just published. He also spoke of 

 the plan of publishing a volume of memoirs to commemorate 

 the one hundredth anniversary of the foundation of the 

 Academy, and proposed that a note should be placed upon 

 the notice of the next meeting requesting members who may 

 have papers which could form" a portion of the contemplated 

 volume to notify the Recording Secretary. 



Professor Charles R. Cross presented the following papers: — 



" Photometric Researches." By William H. Pickering. 



