The hall was packed, not only with men, but with recording and television machines. I read the manifesto (Russell=Einstein Manifesto) )and the list of signatories and explained how and why it had come into being. I then, with Rotblat's help, replied to questions from the floor. The journalistic mind, naturally, was impressed by the dramatic way in which Einstein's signature had arrived.
Source: The Autobiography of Bertrand Russell, v.3 chap. 2: At home and abroad, 1969
More info.: https://russell-j.com/beginner/AB32-190.HTM