equalize the core slid smoothly into place. Once the assembly was
complete many of the men took a welcome relief and went swimming in
the water tank east of the McDonald ranch house.

The next morning the entire bomb was raised to the top of the 100 foot
steel tower and placed in a small shelter. A crew then attached all
the detonators and by 5 p.m. it was complete.



The test


Three observation points were established at 10,000 yards from ground
zero. These were wooden shelters protected by concrete and earth.
The south bunker served as the control center for the test. The
automatic firing device was triggered from there as key men such as
Dr. Robert Oppenheimer, head of Los Alamos, watched. None of the
manned bunkers are left.

Many scientists and support personnel, including Gen. Leslie Groves,
head of the Manhattan Project, watched the explosion from base camp
which was ten miles southwest of ground zero. All the buildings at
base camp were removed after the test. Most visiting VIPs watched
from Compania Hill, 20 miles northwest of ground zero.

The test was scheduled for 4 a.m. July 16, but rain and lightning
early that morning caused it to be postponed. The device could not be
exploded under rainy conditions because rain and winds would increase
the danger from radioactive fallout and interfere with observation of