342 • MAUD COMMITTEE
MAUD COMMITTEE.In 1939 (Sir) George Thomson, Imperial Col-
lege’s professor of physics since 1930, was engaged in military ap-
plications of science, having served in the Royal Flying Corps during
World War I and later worked on aerodynamics at theCavendish
Laboratory. He was commissioned by (Sir) Henry Tizard, formerly
the Royal Air Force’s assistant controller of experiment and research
and an expert on radar, to study the Frisch-Peierls report on the pos-
sibility of developing an atomic bomb. Thomson’s verdict, which he
came to regret, was that the possibility ‘‘seemed likely, though not
certain’’ using heavy water, which was unavailable in any large
amounts, and that the military value of such a weapon ‘‘seemed too
remote to justify further work in wartime,’’ offering odds of 100,000
to 1 against success. As he later remarked, ‘‘If this conclusion now
seems disgraceful blindness I can only plead that to the end of the
war the most distinguished physicists in Germany thought the same.’’
Indeed, he was convinced that the prospects of a superbomb were so
poor that he recommended to Tizard that ‘‘we should let it be known
to the enemy by various means that we had, in fact, got encouraging
results; that the experiments were progressing favorably, and that
great things were expected of them.’’
In the absence of any other suitable body in Whitehall to consider
such matters, Tizard gathered together a committee of scientists to
examine the claims made by Frisch andRudolf Peierls, and it met
in the main committee room on the ground floor of the Royal Society,
at Burlington House, in April 1940. Among those present was John
Cockcroft, as assistant director of research at the Ministry of Supply;
Professor Alexander Hill, secretary of the Royal Society; James
Chadwick; and Thomson, who acted as secretary.
By the time the Thomson Committee met for a second time a fort-
night later, on 24 April, the attitude of mild skepticism had been
transformed, not least by the sheepish admission made by Chadwick,
who reported that he had started experimenting with fast-neutron
fission with his new cyclotron in Liverpool and had reached the iden-
tical conclusions as Frisch and Peierls, but had been reluctant to say
so until he had conducted further research, having originally believed
that it would take 30 or 40 tons of uranium to achieve critical mass.
Accordingly, the committee ‘‘generally was electrified by the possi-
bility’’ that a uranium bomb was a truly practical proposition after
all.