An enjoyable research moment is when historical actors, who you thought were apart, intersect. Albert Wattenberg was a physicist who helped out during the Manhattan Project but then mostly went into academia postwar. Harold Lichtenberger was a key lieutenant of Walter Zinn in designing and building key prototype reactors after the war. I hadn’t really been aware that they had a time together until the Chicago archives delivered an interview of Wattenberg (as part of an Argonne history project) in 1992. By now aged 75, here he describes working on the world’s first reactor, drilling holes in graphite, the holes later holding uranium fuel:
Harold Lichtenberger, who was very talented and knowledgeable about machine shop practice also, decided we could make our own tools out of old files. So he and I worked on this. We would make sixty holes before we had to re-sharpen them. We had to drill forty thousand holes. He and I took the responsibility for making sure that there was a set of tools that were sharp. That’s a lot of grinding. There was no jig; we did it by hand, with our eyeballs.

NOTE
Wattenberg, Albert. 1992. Dr. Albert Wattenberg, Argonne National Laboratory History Project, Interviewed Apr. 24, 1992. “Dr. Albert Wattenberg Interview; April 24, 1992,” Box 1 of 1, Historical Materials Relating to Albert Wattenberg, RG 326, National Archives and Records Administration–Great Lakes Region (Chicago).