| 1930 BLOSSER Railway Traffic Controlling Art |
| 1930 UNION Railway Traffic Controlling Art |
| 1930 CRAIN Controlling Ships' Steering Gears Art |
| 1930 BUCK Railway Brake Controlling Art Print |
| 1930 COBOURN Controlling Railway Switches Art |
| 1930 WOOD Railway Switch Controlling Art Print |
| 1930 THOMPSON Railway Traffic Controlling Art |
| 1930 BOSSART Railway Traffic Controlling Art |
| 1930 ALEXANDER Railway Traffic Controlling Art |
| 1930 COLEMAN Railway Traffic Controlling Art |
| 1930 UNION Controlling Railway Switches Art |
| 1930 MCCANN Railway Traffic Controlling Art |
| 1930 BAUGHMAN Railway Traffic Controlling Art |
| 1930 VANHORN Railway Traffic Controlling Art |
| 1930 WALLACE Railway Traffic Controlling Art |
| 1930 GEIGER Railway Traffic Controlling Art |
| 1930 WAYNE Controlling Means Airplanes Art Print |
| 1930 AX Controlling Mechanism Aeroplanes Art |
| 1930 HANDLEY Means Controlling Aeroplanes Art |
| 1930 NETTLETON Railway Traffic Controlling Art |