Donald A. Hall Estate Collection

Donald A. Hall Sr. Engineering Pocket Slide Rule and Case (Circa 1919)

A primary calculation tool of early twentieth-century aerospace engineering, this vintage white celluloid pocket slide rule and worn leather slipcase was owned and used by Donald A. Hall Sr. Acquired during his mechanical engineering studies at the Pratt Institute and utilized during his experimental aerodynamic work at Curtiss, this analog calculating instrument served as Hall's portable tool for computing wing loading, lift-to-drag ratios, and structural stress factors.