 At age 21 he invented a "car replacer", a device to guide derailed railroad cars back onto the tracks, and a reversible frog, a device used with a railroad switch to guide trains onto one of two tracks.At about this time, he witnessed a train wreck where two engineers saw one another, but were unable to stop their trains in time using the existing brakes.Brakemen had to run from car to car, on catwalks atop the cars, applying the brakes manually on each car.