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taking action along this line it would not be necessary officially to 
 
disclose that the uranium content of the ore is the point of interest; 
 
action might be taken on the ground that it is of value to secure a 
 
stock of the ore on account of its radium content for possible future 
 
extraction of the radium for medical purposes.
 
     Since it is unlikely that an earnest attempt to secure a supply
 
of uranium will be made before the possibility of a chain reaction has 
 
been visibly demonstrated, it appears necessary to do this as quickly 
 
as possible by performing a large-scale experiment. The previous experi-
 
ments have prepared the ground to the extent that it is now possible clearly 
 
to define the conditions under which such a large-scale experiment would have 
 
to be carried out. Still two or three different setups may have to be tried 
 
out, or alternatively preliminary experiments have to be carried out with 
 
several tons of material if we want to decide in advance in favor of one 
 
set-up or another. These experiments cannot be carried out within the 
 
limited budget which was provided for laboratory experiments in the past, 
 
and it has now become necessary either to strengthen - financially or other-
 
wise - the organizations which concerned themselves with this work up to 
 
now, or to create some new organization for the purpose. Public-spirited 
 
private persons who are likely to be interested in supporting this enter-
 
prise whould be approached without delay, or alternatively the collaboration 
 
of the chemical or the electrical industry should be sought.
 
              The investigations were hitherto limited to chain reactions based 
 
on the action of slow neutrons. The neutrons emitted from the splitting 
 
uranium are fast, but they are slowed down in a mixture of uranium