Complex sentence: Its first meeting on 21 October 1939, was attended by Szilard, Teller and Wigner, who persuaded the Army and Navy to provide $6,000 for Szilard to purchase supplies for experiments--in particular, more graphite.
Split into simpler sentences: Its first meeting on 21 October 1939, was attended by Szilard, Teller and Wigner. The scientists persuaded the Army and Navy to provide $6,000 for Szilard to purchase supplies for experiments--in particular, more graphite.