attributes the name to J. Robert Oppenheimer, the scientific head of
the Manhattan Project. According to this version, the well read
Oppenheimer based the name Trinity on the fourteenth Holy Sonnet by
John Donne, a 16th century English poet and sermon writer. The sonnet
started, "Batter my heart, three-personed God."[2] Another version of
the name's origin comes from University of New Mexico historian Ferenc
M. Szasz. In his 1984 book, The Day the Sun Rose Twice, Szasz quotes
Robert W. Henderson head of the Engineering Group in the Explosives
Division of the Manhattan Project. Henderson told Szasz that the name
Trinity came from Major W. A. (Lex) Stevens. According to Henderson,
he and Stevens were at the test site discussing the best way to haul
Jumbo (see below) the thirty miles from the closest railway siding to
the test site. "A devout Roman Catholic, Stevens observed that the
railroad siding was called 'Pope's Siding.' He [then] remarked that
the Pope had special access to the Trinity, and that the scientists
would need all the help they could get to move the 214 ton Jumbo to
its proper spot."[3]

The Trinity test was originally set for July 4, 1945. However, final
preparations for the test, which included the assembly of the bomb's
plutonium core, did not begin in earnest until Thursday, July 12. The
abandoned George McDonald ranch house located two miles south of the
test site served as the assembly point for the device's core. After
assembly, the plutonium core was transported to Trinity Site to be
inserted into the thing or gadget as the atomic device was called.
But, on the first attempt to insert the core it stuck! After letting
the temperatures of the core and the gadget equalize, the core fit
perfectly to the great relief of all present. The completed device
was raised to the top of a 100-foot steel tower on Saturday, July 14.
During this process workers piled up mattresses beneath the gadget to