Dayton, Ohio was another site of the secret Manhattan Project work. In July 1943, Oppenheimer assigned Charles A. Thomas the task of separating polonium for use as the initiator of the bombs.
Polonium, which was discovered by physicist Marie Curie, is a peculiar, soft metal which is dangerous to inhale and very difficult to produce. When polonium comes in contact with with beryllium, they produced the neutrons necessary to ignite the nuclear reaction.
As Monsato Chemical Company’s research director, Thomas not only convinced Monsato to undertake the polonium work, he also persuaded his mother-in-law, Mrs. Harold E. Talbott, to let them use the family’s grand Runnymede Playhouse with its giant ballroom, indoor tennis courts, and other facilities for the separation process.