ay
A note of special interest is thet some indication of the fireball

size as a function of yield is found in » compsrison of the ERT data of
2ae een

rerates =
e burns f 1'd.d. were produced
the present shot Lerg

by exposure to the FA «t Runit

__

At essentially the same distance, much
smaller lesions averaging only 1/4 dyd. were produced at Japtan by the near
:

nominal weapon,
At this distance the smail difference of 1/2mile has a nesligible effect
upon the size of the image of the fireball upon the retina,
Stargered Shutters

These shutters were open at zero time and closed in pairs at intervals
increasing by 10 msec through 100 msec,

The remainder of this series, also

open at zero time, closed in pairs at 120, 250, and 1000 msec.

The exact

time of closing will be determined at a ‘ater date from evaluation of the
high speed photogrephy sccomplished during the flesh interval.

The time for

the minimur following the first pulse is celeulated at 50 + 2 msec.

It is

of interest that 4 of 15 rabbits received burns during this period.

In

fact, 2 animals appear to have sustained retinal damage as early as the
first 10 msee of the flash,
burning duri

At compsreble distances the incidence of

the first pulse alone (0 to 11 oseRE <>< 0 to
) is about 25 percent for both shots,

50 msec

All of the lesions from the first wave of the power pulse were mild

and small, ranging from pin~point to ebout 1/3 d.d. in size.

No burns

were produced behind shutters open in the range between O to 60 and O to
250 msec except in one case at the latter limit where a small double burn
occurred,

This apparent inconsistency in the data is unexplained at the

wae

ue

-

29

-

er

XW

moment.

Select target paragraph3