Penna. Railroad Signal Linens
39-S
Circuits for Electro-Pneumatic
Automatic Home & Distant Signals
1904
200-S4
Mechanical Interlocking Machine
1909
229-S1
Diagram Showing
Rocking Shaft Leadout Construction
1910
239-S
Standard Semaphore Spectacles
1910
252-S1
Typical Arrangement of Mechanical Signals
Operated by Machine and Ground Levers
1911