BY ANDREW LEWIS

RADIOACTIVITY IS FIRST OBSERVED

LEO SZILARD CONCIEVES THE IDEA OF NUCLEAR CHAIN REACTION

SZILARD FILES FOR PATENT OF "ATOMIC BOMB"

GERMAN SCIENTISTS DEMONSTRATE NUCLEAR FISSION

EINSTEIN SIGNS LETTER AND SENDS TO ROOSEVELT

FIRST CONTROLLED NUCLEAR CHAIN REACTION

JAPAN BECOMES PRIMARY TARGET FOR AN "ATOMIC BOMB"

"THE GADGET" IS TESTED, FIRST ATOMIC BOMB

HIROSHIMA IS BOMBED

NAGASAKI IS BOMBED

JAPAN FORMALLY SURRENDERS, WWII ENDS