Donald A. Hall Estate Collection

Hall Aeronautical Development Company Custom Drafting Scale Ruler (Circa 1934)

An exceptional corporate artifact from Donald A. Hall Sr.'s private post-Ryan aerospace enterprise: a professional 12-inch boxwood and celluloid drafting scale custom-imprinted with the company name "HALL AERONAUTICAL DEVELOPMENT CO." This precision tool was utilized by Hall in his San Diego drafting rooms to lay out the experimental Hall X-1 tandem-wing prototype and draft the complex mechanical patent schematics for his stall-resistant aircraft designs under U.S. Patent 1,895,458.