Martin Sherwin: The work must have been sort of very frustrating for a while, before that [Stanislaus] Ulam-[Edward] Teller breakthrough [on the hydrogen bomb].

Ed Hammel: Well, sure. There was— 

Sherwin: What were you doing at that time?

Hammel: At that point, I continued with having this group in charge of properties of plutonium. But one of the things that we were very interested in was the low temperature properties, the specific heat specifically, of plutonium.