| 1944 GEN Highway Crossing Signal System Art |
| 1944 FOX PROD CO Signal Device Patent Print Art |
| 1944 GEN RAILWAY SIGNAL CO Oscillating Code Transmitter |
| 1944 UNION SWITCH SIGNAL CO Electrical Control |
| 1944 SUBMARINE SIGNAL CO Submarine Signaling Art |
| 1944 UNION SWITCH SIGNAL CO Indication Art |
| 1944 PFLASTERER GEORGE Light Signal Patent Print |
| 1944 GUSTAV Electromagnetic Signal Hooter Patent |
| 1944 STANDARD Electromagnetic Audible Signal Art |
| 1944 WALLACE TIERNAN INC Sound Signal Art Print |
| 1944 KENERSON Electromagnetic Audible Signal Art |
| 1944 HITT Natural Colors Floating Signal Patent |
| 1944 UNION SWITCH & SIGNAL CO Light Signal Art |
| 1944 UNION SWITCH SIGNAL CO Coded Railway Signaling |
| 1944 ROBERT DEMPSEY Automobile Signal Patent |
| 1944 HOLT Surface Marking Signal Patent Print |
| 1944 FORESMAN EDWIN Table Signal Patent Print |
| 1944 UNION Signal System Using Phase Modulation |
| 1944 TIZZARD Highway Crossing Signal Control System |
| 1944 UNION SWITCH SIGNAL CO Switch Control System |
| 1944 UNION SWITCH SIGNAL CO Railway Braking Art |
| 1944 UNION Highway Crossing Signal Control System |
| 1944 UNION SWITCH SIGNAL CO Railway Signaling System |
| 1944 EAGLE SIGNAL CORP Timing Mechanism Patent |
| 1944 UNION SWITCH SIGNAL CO Signal Control Art |
| 1944 LOVELL DRESSEL INC Socket Switch Signal Lamps |
| 1944 GEN RAILWAY SIGNAL CO Highway Crossing Gate |
| 1944 UNION SWITCH SIGNAL CO Control Art Print |
| 1944 PLACE Signal System Using Phase Modulation |
| 1944 SCHATZMAN Socket Switch Signal Lamps Art |
| 1944 GEHRING FRED Signal Apparatus Patent Print |
| 1944 UNION SWITCH SIGNAL CO Train Detecting Reporting |
| 1944 SUBMARINE SIGNAL CO Submarine Signaling |
| 1944 UNION SWITCH & SIGNAL CO Electric Lock Art |
| 1944 MACKAY Sound Signal Apparatus Patent Print |
| 1944 UNION SWITCH SIGNAL CO Track Indication System |
| 1944 UNION SWITCH SIGNAL CO Coded Track Circuits |
| 1944 UNION SWITCH SIGNAL CO Coded Signaling System |
| 1944 UNION SWITCH SIGNAL CO Railway Track Circuit |
| 1944 SHANNON ROY Signal Lantern Patent Print Art |
| 1944 UNION SWITCH SIGNAL CO Circuit Controller |
| 1944 DODD Signal Control Apparatus Patent Print |
| 1944 LESNICK Gun Operation Signal Mechanism Art |
| 1944 STOLLER Signal Controlling Fusee Patent |
| 1944 AMERICAN SIGNAL Signaling System Art Print |
| 1944 UNION SWITCH SIGNAL CO Traffic Locking Circuit |
| 1944 MILLER ROBERT Signal Device Patent Print |
| 1944 PATRICK JACKSON Signal Pistol Patent Print |
| 1944 UNION SWITCH SIGNAL CO Attaching Means Art |
| 1944 UNION SWITCH SIGNAL CO Electrical Control System |
| 1944 UNION SWITCH SIGNAL CO Railway Switch Operating |
| 1944 U. S. Army M-210 Signal Corps Message Book |
| Dated 1944 "Signal Call" Devise World War 11- Lights up |
| WWII 1944 Army Signal Corps PRESS PHOTO German Capture |
| 1944 Gamewell fire alarm signal box & siren photo ad |
| 1944 Southern Switch red fire alarm signal pull box ad |
| Dated 1944 "Signal Call" Devise World War 11- Lights up |
| Aug. 1944 notebk:Union Switch & Signal Co. |