648. ARMING THE HIROSHIMA BOMB-MORRIS R. JEPPSON (b. 1921) American Army Air Corps officer, navigator of the Enola gay during its mission to Hiroshima on August 6, 1945. Superb content A.L.S., 2pp. 4to., [n.p., n.d.], describing the arming of the Hiroshima atomic bomb. In small part: "...Regarding my participation in the flight of the Enola Gay B-29 to deliver the first atomic bomb 6 Aug. 1945...shortly after the Enola Gay lifted off, Captain Parsons, the mission commander, climbed into the bomb bay. My responsibility was to monitor, with a small console, the electrical condition of the fuzing system of the bomb...I climbed into the bomb bay and exchanged an electrical 'plug', that permitted in-flight testing of the bomb circuits, with a 'plug' that connected the automatic fuzing with the circuits in the bomb with the powder to fire the gun when Little Boy reached elevation above ground of 1400-1800 feet (while it was falling at the speed of sound). The switching of the two plugs armed the bomb...I was the last person to touch the Hiroshima Bomb. The bomb was released from Enola Gay at 09:15 Tinian time 6 August 1945. Time of fall from the plane, flying then at 30,000 feet, was 43 seconds. It hit close to the aiming point on the Aioi Bridge in Hiroshima...moments later from Van Kirk's navigator window I saw the churning mass of smoke and flame surging out from Hiroshima. I realized there was terrible destruction and loss of life on the ground below. Colonel Tibbets, the pilot and commander of the 509th Bomb Group, had quickly turned the plane away to minimize shock wave blast and to avoid the mushroom cloud that was rising rapidly upward. The extent of the damage depends upon the size of the nuclear detonation, the height above the ground, and geography of the target...". In very fine condition, an historic content letter worthy of framing. 1,500 - 2,000