| 1939 RICHARDSON CECIL Propeller Patent Print Art |
| 1939 WEATHERWAX Fishtail Propeller Patent Print |
| 1939 MANNING RAY Propeller Patent Print Art |
| 1939 LUDWIG HOFFMANN Air Propeller Patent Print |
| 1939 FRANK Airplane Propeller Blade Patent Print |
| 1939 BELFIELD WILLIAM Propeller Patent Print Art |
| 1939 HENRY WEISSMANN Propeller Patent Print Art |
| 1939 CAIRNS CORP Variable Pitch Propeller Patent |
| 1939 PEREY Variable Pitch Propeller Patent Print |
| 1939 MERTENS GABRIEL Propeller Patent Print Art |
| 1939 W W KEITH Propeller Patent Print Art |
| 1939 ROBERT B MENEFEE Fishtail Propeller Patent |
| 1939 CALDWELL FRANK Propeller Drive Patent Print |
| 1939 LAMPTON Controllable Pitch Propeller Patent |
| 1939 AUSTIN Propeller Control Mechanism Patent |
| 1939 LITTLEJOHN ORVILLE Propeller Patent Print |
| 1939 TROLLER THEODORE Propeller Patent Print Art |
| 1939 BERLINER Variable Pitch Propeller Patent |
| 1939 ENGINEERING AND RES CORP Propeller Patent |
| 1939 CAIRNS Variable Pitch Propeller Patent |
| 1939 VICTOR Propeller Patent Print Art |
| 1939 CALDWELL Releasable Propeller Drive Patent |
| 1939 PLATT Variable Pitch Propeller Patent Print |
| 1939 JOHN SQUIRES Propeller Blade Patent Print |
| 1939 WILLIAM Propeller Governor Patent Print Art |
| 1939 VICTOR TELFER Propeller Patent Print Art |
| 1939 UNITED AIRCRAFT CORP Propeller Blade Patent |
| 1939 BENDIX PROD CORP Propeller Patent Print Art |
| 1939 HICKS ELIAS Propeller Patent Print Art |
| 1939 THOMAS Propeller Shaft Protector Patent |
| 1939 AUSTIN ELLSWORTH Propeller Patent Print Art |
| 1939 VICTOR Air Propeller Blade Patent Print Art |
| 1939 UNITED AIRCRAFT CORP Propeller Drive Patent |
| 1939 PETERSON PER Propeller Patent Print Art |
| 1939 THOMAS Controllable Pitch Propeller Patent |
| 1939 MOHLER JAMES Aircraft Propeller Patent |
| 1939 MERTENS Propeller Patent Print Art |
| 1939 PIATT Variable Pitch Propeller Patent Print |
| 1939 BERLINER HENRY Propeller Patent Print Art |