Scientists Test "Fool-Proff" Dynamite -- "Playing with dynamite" is all right, say these three scientists - if the explosive happens to be exploded only with a certain type of percussion cap. Left to right are Charles W. Bennett, of Paulsbord, N. J.; Dr. W. E. Kirst, of the E. I. Dupont De Nemours Co., Laboratory, where the dynamite was developed, and R. Paul Sweeney, of Wenonah, N.J. The Dynamite resisted sledge-hammer blows when this test was made in Philadelphia, Feb. 20. February 20, 1935. (Photo by Wide World Photo).