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.
However, horse owners should have an idea of how their individual horses react to hoof testers when they are sound and in regular use. Asking a veterinarian or farrier to demonstrate the use of this tool is a good way for the owner to gauge the baseline sensitivity of a particular horse.