wanting to proceed to B. The first one is despatched with a ticket, and the second also, but the third, or last, must carry on the engine what is known as the train staff, a straight piece of wood somewhat resembling a constable's staff, but coloured and lettered in accordance with the particular section of line it refers to. The box containing the "tickets" can only be unlocked by means of the train staff, which is really the key, and no train can enter the opposite end of the section until the train staff itself arrives at that end, so that it is impossible for two trains to meet in opposite directions, and the proper distance between trains proceeding in the same direction is maintained by fixed signals and the block telegraph, the same as on double lines. Where the branch is a long one, it is divided into sections, with crossing places at convenient intervals, and each section has its own staff and set of tickets, and is worked separately in the manner described.
This system of working single lines, although it has been altered and improved upon in many ways, until it may now be considered to be almost perfect, both as to safety and convenience, was originally devised by Mr. Henry Woodhouse, until lately one of the engineers to the London and North-Western Company, for the working of a long tunnel, called the "Standedge Tunnel," on the Huddersfield and Manchester railway, of which he had charge nearly forty years ago, and was authorised generally by the Board of Trade, and included in their requirements in 1860.
Some single lines of short length, and where the traffic is light, are worked by a single engine in steam, and this fact, of course, supersedes the necessity for any special precautions such as those already described.
