MINUTES OF THE INSTITUTE. 



May 5, 1910. — Annual meeting of the Institute. In 

 the absence of the president and vice president, Albert S. 

 Barker was made president pro tem. Routine business and 

 annual reports of oflficers and committees. Albert J. Williams, 

 of Media, was elected to membership. The annual election 

 of officers was held, with the following result : — 



President, T. Chalkley Palmer 



First Vice President, Henry h- Broomall 



Second Vice President, Charles Potts 



Secretary, B. M. Underhill 



Treasurer, C. M. Broomall 



Librarian, Henrietta K. Broomall 



Board of Curators, Edgar T. Miller and Homer E. Hoopes 



The following acquisitions to the librar}- were announced : 

 "Twenty Years in Congress," by James G. Blaine ; "History 

 of Pennsylvania Volunteers," Volumes III, lY and V. Fol- 

 lowing the business meeting a lengthy discussion was had 

 concerning comets and other astronomical phenomena. Albert 

 S. Barker exhibited a novel form of polariscope, consisting of 

 two mirrors of black glass so arranged that the light polarized 

 by reflection from the first mirror is received upon the second 

 mirror at the polarizing angle and in the plane of extinction ; 

 and provided with a stage placed between the mirrors for the 

 support of the films of mica or selenite, crystallizations, etc. 

 In this apparatus chromatic effects are produced such as are 

 obtained in the ordinary polariscope, when polarizer and 

 analyzer are crossed. Mr. Barker also gave a demonstration 

 of the real image formed when rays from an object are 

 received upon a concave mirror and converged by reflection 

 to a focal plane in front of the mirror. After further discus- 

 sion the meeting adjourned. 



June 2, 1910. — Regular monthly meeting, with Presi- 

 dent T. Chalkley Palmer in the chair. Reports of committees 



