Signed First Day Cover.
Auto safety pioneer long before Ralph Nader popularized the topic in "Unsafe at Any Speed," this University of Minnesota mechanical engineering professor (1931-63) patented the first retractable safety seat belt in 1963 and the "black box" flight recorder in 1960; he also improved hydraulic bumpers, dashboards and collapsible steering columns. Signed First Day Cover, 6½" X 3½", cancelled in Baltimore, Maryland on 3 September 1965 and with "Firsy Day of Issue" boldly stamped. Single 5-cent "Stop Traffic Accidents" stamp at upper right. Fine. At lower left, beneath the postal cancellation, Ryan signs large and bold in blue ballpoint. Attractive and very scarce. Item #24360
Price: $100.00