Philadelphia: The American Philosophical Society 1949. First Edition. , 521-548, iv pages. 8 x 10.5 inches. Printed tan wrappers. Signature of previous owner (Penn Professor of Physics Emeritus Sidney Bludman) at top of front wrapper, and notations in his hand throughout. Minor browning to extremities, wear to spine (which is quite thin to begin with) obliterating the center of the printed title. Good. Wraps. 
Contains articles by Wigner, Eugene P. , Robertson, H. P. ,Clemence, G. M. and Weyl, Hermann as well as "Dr. Albert Einstein and American Colleagues, 1931" which reproduces Einstein's handwritten response to the welcome of scientists at CIT in 1931, and also Dr. Millikan's introduction.