Albert Einstein
Old Grove Rd.
Nassau Point
Peconic, Long Island

August 2nd, 1939

F. D. Roosevelt,
President of the United States,
White House
Washington, D.C.

Sir:

Some recent work by E. Fermi and L. Szilard, which has been communicated to me
in manuscript, leads me to expect that the element uranium may be turned into
a new and important source of energy in the immediate future. Certain aspects
of the situation which has arisen seem to call for watchfulness and, if
necessary, quick action on the part of the Administration. I believe therefore
that it is my duty to bring to your attention the following facts and
recommendations:

In the course of the last four months it has been made probable - through the
work of Joliot in France as well as Fermi and Szilard in America - that it may
become possible to set up a nuclear chain reaction in a large mass of uranium,
by which vast amounts of power and large quantities of new radium-like
elements would be generated. Now it appears that almost certain that this
could be achieved in the immediate future.

This new phenomenon would also lead to the construction of bombs, and it is
conceivable - but much less certain - that extremely powerful bombs of a new
type may thus be constructed. A single bomb of this type, carried by boat and
exploded in a port, might very well destroy the whole port together with some
of the surrounding territory. However, such bombs might very well prove to be
too heavy for transportation by air.

The United States has only very poor ores of uranium in moderate quantities.
There are some good ores In Canada and the former Czechoslovakia, while the
most important source of uranium is Belgian Congo.

In view of the situation you may think it desirable to have some permanent
contact maintained between the administration and the group of physicists
working on chain reactions in America. One possible way of achieving this
might be for you to entrust with this task a person who has your confidence
and who could perhaps serve in an inofficial capacity. His task might comprise
the following:

a) to approach Government Departments, keep them informed of the further
development, and put forward recommendations for government action, giving
particular attention to the problem of securing a supply of uranium ore for
the United States;

b) to speed up the experimental work, which is at present being carried on
within the limits of the budgets of University laboratories, by providing
funds, if such funds be required, through his contacts with private persons
who are willing to make contributions for this cause, and perhaps also by
obtaining the cooperation of industrial laboratories which have the necessary
equipment.

I understand that Germany has actually stopped the sale of uranium from the
Czechoslovakian mines which she has taken over. That she should have taken
such early action might perhaps be understood on the ground that the son of
the German Under–Secretary of state, von Weiszäcker, is attached to the
Kaiser-Wilhelm-Institut in Berlin where some of the American work on uranium
is now being repeated.

Yours very truly,
A. Einstein
(Albert Einstein)

