July and no later than 23 July. On 30 June, the earliest firing date
was moved to 16 July, even though better weather was forecast for 18
and 19 July. Because the Allied conference in Potsdam, Germany, was
about to begin and the President needed the results of the test as
soon as possible, the TRINITY test organization adjusted its schedules
accordingly and set shot-time at 0400 hours on 16 July (3; 12; 14).

The final preparations for the detonation started at 2200 on 15 July.
To prevent unnecessary danger, all personnel not essential to the
firing activities were ordered to leave the test site. During the
night of 15 July, these people left for viewing positions on Compania
Hill,* 32 kilometers northwest of ground zero. They were joined by
several spectators from LASL (3; 12).

* "Compania" also appears as "Compana," "Campagne," or "Compagna" in
various sources.

Project personnel not required to check instruments within the ground
zero area stationed themselves in the three shelters or at other
assigned locations. The military police at Guard Posts 1, 2, and 4
blocked off all roads leading into the test site, and the men at Guard
Post 8, the only access to the ground zero area from the Base Camp,
ensured that no unauthorized individuals entered the area (9; 12).

At 0100 hours on 16 July, military policemen from Guard Posts 3, 5, 6,
and 7 met to compare their logs of personnel authorized to be in the
ground zero area. The guards then traveled along the access roads to
clear out all project personnel. As individuals left for their
assigned shelters or stations, their departures from the test area
were recorded in the military police logs. By 0200 the area sweep was