130 BULLETIN OF THE 



trouble to use it will soon see to which of the three classes any 

 particular objective they may test belongs. 



Mr. Woodward also made remarks on 



THE RULINGS ON GLASS BY MR. ROGERS, OP CAMBRIDGE. 



(abstract. ) 



This communication was a preliminary one. Mr. Woodward 

 showed photographs, which he had made, of two of Mr Rogers, 

 rulings magnified about 1050 diameters, and compared them with 

 rulings by Powell & Lealand, Nachet and Nobert. The object 

 of the photographs was to show the quality of the lines. Those 

 of Mr. Rogers appeared to have been ruled with a faulty point, 

 and were each accompanied on one side by a series of faint 

 parallel lines. That these were not due to difTraction was de- 

 monstrated by revolving the ruling (on the stage of the micro- 

 scope) while the illuminating pencil remained stationary. The' 

 faint parallel lines revolved with the ruling. 



The rulings of Nobert were superior in the quality of the lines 

 to any of the others. The reporter expected to examine more 

 rulings by Mr. Rogers and others, and would make hereafter a 

 fuller communication. 



124th Meeting, May 5, 181t. 



The President in the Chair. 

 Thirty-eight members and visitors present. 



The General Committee reported the following resolutions 

 respecting the late Dr. B. F. Craig, which, after appropriate 

 remarks by Messrs. Henry, Parker, E. B. Elliott, Hilgard, 

 and Woodward, were adopted. 



Whereas the members of this Society have learned with sincere 

 grief of the death of one of its original members, Dr. Benjamin 

 Eaneuil Craig, at the age of 49, at his residence in Washing- 

 ton, on April 10th, 18tY, after a very protracted and painful 

 illness, which he endured with uncomplaining fortitude ; there- 

 fore be it 



Resolved, That in considering the death of Dr. Craig, this 

 Society deplores the loss of a member who was one of its 

 founders, as well as one of the original members of the scientific 



