;j(K) MOTIVE POWER EMPLOYED

when the goods are all conveyed in one direc-tion, where the distances are shorty the motionslow, and where, perhaps, the necessity for thecarriages passing each other, do not frequentlyoccur. In this form of road the carriages willalways continue along the main line of road,unless diverted into the passing by the move-able rail, previously described, the attendanthaving to put it into the proper position,whenever the carriages are likely to meet eachother. Thus, if a train of carriages, comingalong the main line, in the direction A A',are likely to meet another train coming in theopposite direction, then the attendant putsthe moveable rail into the proper situation,when the empty train proceeds either along a 13,or b I3i, as the case may happen ; and the car-riages pass each other.

This form of siding is much, or indeed almostinvariably, used in all the Rail-ways, wheretliu goods are to be conveyed in one directiononly, the empty carriages being the returningload ; such as the conveyance of coals fromthe coal-pits to the shipping places. In thesecases, the loaded carriages always keep themain line, and the empty carriages pass intothe siding ; the moveable rail being placed onthat end of the crossing towards which theempty carriages are proceeding. These mo-