Evening star. [volume] (Washington, D.C.) 1854-1972, 1962-12-02

The air was choking with the
black graphite dust that turned
the floors treacherously slick as
1t fell. 1T would have been a
wonderful dance floor" Leona
Marshall unused recently.
Graphite pliers used to slide
the blocks along the floor like
bowling balls" to save carrying
them. Left INTENDED on the
slightest uneven surface, the
blocks used to slip off smashing
toes and fingers.
Du Pont officials were Mortified
at the lack of safety precautions
when they Joined the project in
late 1912, Allison recalled. They
made every one wear metal tipped
shoes. They got here just in time
or we'd all been in the hospital"
AS purer and purer metals ar
rived during the late summer,
Fermi found his measurements of
the test piles getting increasingly
close to the point where the pile
would go critical, that is, achieve
a chain reaction.
Many Test Piles Built
Over 80 test piles we're built.
THE day shift would build one,
the night shift would take
measurements and tear it down
and we'd come in the next day
and build a new one" Mobiles said.
Each day from each pile Fermi
would figure out what it all
meant" said Herbert Kubitschek,
another of the pliers. 1T would
have taken the other physicists
days. The next morning we would
have our orders for the next pile.
Fermi had to be rapid and he
had to be certain. There were no
IBM calculators in those days"
Fermi's brilliance, his simplicity,
his warmth, inspired faith.
He eschewed calculating ma
chimes, preferring to figure with
his small 5-inch slide rule. He
once explained his success to
Filbey saying smilingly: II had
a wonderful library" In answer to
another question Fermi once said
IT don't know what the books
say. But this is what they should
say"
Fermi inspired affection. Most
of the men who worked with him
who are still in the Chicago area
have a picture Of the late scientist
in their offices. He inspired de-
votion. from top to bottom.
Despite misgivings from the
security echelon, Fermi felt the
graduate students among his
workers had a right to know the
basics of what they were doing
He illustrated his lectures to them
on brown wrapping paper. care
fully burning 1t afterwards. The
students in turn once tried with
modest success to teach Fermi
to play baseball at a picnic.
The Time to Build
BY mid-November Fermi was
ready. He and his scientists had
found the optimum arrangement
for the uranium through the pile
they had calculated the necessary
size lin fact the last shipment
for the pile arrived December 2
the day 1t went critical. II wa,
time to build.
Fittingly, Fermi was near by
when the last pile was to begin
"Enrico. you want TO lay tho
cornerstone?" some one asked
With a grin Fermi picked up thu
first block and laid II In place.
Row by row. layers of graphite
alternating with uranium and pei
lets OF uranium oxide. the pill,
grew. The structure. known Of
ficially as CPL dor Chicago
pile), was shaped like a doorknol
TO give the maximum amount o
mass with a minimum Of surface
through which neutrons coult
escape. Knuth shored II as II ros,
with 4 by IS.
BY December /. 456 tons o
graphite and uranium had beer
stacked. a total OF 10000 blocks.
That evening linn and Ander
son measured the nuclear activit,
inside the pile. II was ready
They shut down the control rod
and went home TO bed. a las
nights sleep before the atomi
dawn.
The Big Doy Arrives
Maronde remembers the mex
day as bitterly cold, down nea
zero. He stood by the gate stamp
ing his feet In the snow as tn