The pedrail wheel is a type of all-terrain wheel developed in the late 19th and early 20th century by Londoner Bramah Joseph Diplock. It consists of a series of "feet" (pedes in Latin) connected to pivots on a wheel. As the wheel travels, pressure exerted by springs within it increases the number of feet in contact with the ground, thus reducing ground pressure and allowing the wheel to negotiate obstacles and uneven ground.