side only.

To illustrate the effects of the flash burn, the following describes a
number of examples found by an observer moving northward from the center of
explosion in Nagasaki. First occurred a row of fence posts at the north
edge of the prison hill, at 0.3 miles from X. The top and upper part of
these posts were heavily charred. The charring on the front of the posts
was sharply limited by the shadow of a wall. This wall had however been
completely demolished by the blast, which of course arrived some time after
the flash. At the north edge of the Torpedo works, 1.05 miles from X,
telephone poles were charred to a depth of about 0.5 millimeters. A light
piece of wood similar to the flat side of an orange crate, was found
leaning against one of the telephone poles. Its front surface was charred
the same way as the pole, but it was evident that it had actually been
ignited. The wood was blackened through a couple of cracks and nail holes,
and around the edges onto the back surface. It seemed likely that this
piece of wood had flamed up under the flash for a few seconds before the
flame was blown out by the wind of the blast. Farther out, between 1.05
and 1.5 miles from the explosion, were many trees and poles showing a
blackening. Some of the poles had platforms near the top. The shadows
cast by the platforms were clearly visible and showed that the bomb had
detonated at a considerable height. The row of poles turned north and
crossed the mountain ridge; the flash burn was plainly visible all the way
to the top of the ridge, the farthest burn observed being at 2.0 miles from
X.

Another striking effect of the flash burn was the autumnal appearance of
the bowl formed by the hills on three sides of the explosion point. The
ridges are about 1.5 miles from X. Throughout this bowl the foliage turned
yellow, although on the far side of the ridges the countryside was quite