Amazing railway velocipede

This afternoon I ran across stories about railway velocipedes and I think it made my day. For instance, this one is amazing at

The railway velocipede shown in the accompanying illustration is an adaptation of the design of the safety bicycle to track service, the machine having a, flanged tire on the front wheel and a blind tire on the rear wheel, and being held upright by a brace carrying a small guide wheel, with flanged tire running on the opposite rail. (...) The space occupied, when thus folded, is only 6 ft. x 1 ft. 6 ins., a little more than that required for a road bicycle.

Why do I blog this? first because it's definitely a nice objects and second because I am impressed by the concept of using infrastructures for other purposes (close to Situationists' concept of d├ętournement), it's very like the skateboarding idea in which you use urban topographies to - mmmh - surf through the city.