Circular Slide Rule, William J. Powell

During the 1920s William J. Powell led a small group of black air enthusiasts in Los Angeles. He established the Bessie Coleman Flying Club in 1929 and sponsored the first all-black air show on Labor Day 1931. As part of his effort to make aviation accessible to African American students, he taught classes on aeronautics at the Bessie Coleman Flying Club. This flight computer was among the equipment he used while teaching.