1961 Death Rheinhold Rudenberg, inventor of electron microscope, dies 1940 Event 1st electron microscope demonstrated (RCA), Philadelphia, Pa 1940 Event RCA demonstrated its new electron microscope in Philadelphia 1888 Birthday Frits Zernike, invented phase-contrast microscope, Nobel 1953 1723 Death Thonis van Leeuwenhoek, biologist/inventor (microscope), dies at 90
