SEPTA cab signal display for the 4-aspect PRR system using position light aspects. Pulse code cab signaling is a form of cab signaling technology developed in the United States by the Union Switch and Signal corporation for the Pennsylvania Railroad in the 1920s.
Measuring your Saddle Seat Size. The easiest way to measure for the appropriate seat size is to measure your upper thigh. Sit in a chair with your feet flat on the ground so that your knees are bent at a 45-degree angle. Be sure your buttocks are touching the back of the chair. Take a measuring tape and run it along your thigh bone, measuring from the end of your knee to the backside of your buttocks.
Be sure to measure in a straight line, and stop measuring at the front of the seat, which is illustrated in the photo by the red line. The Western roping saddle in the photo above has a 16 seat. Measuring English Saddles. English saddles are measured differently than Western saddles.