They had traveled by the third-rail line twenty miles into the country.
He may perfect a third-rail system for use on moving trains.
It was originally on the third-rail system, but was changed into an ordinary overhead trolley seven or eight years ago.
A great rate of speed can be gained with the third-rail system, ten miles having been made in thirteen and a half minutes.
The third-rail system in its simplest form is shown in Fig. 29, which represents a section through the roadbed.