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MOTIVE l’OWEl! EMPLOYED

in the same direction ; by the proper signal,the heavy train passes along fe into the roadA' A, until the other train passes it, when itagain gets upon its former track, by passingalons: d c. In this manner, when the road ispretty straight (which in public lines shouldalways be the case) the carriages will never beinterrupted by each other: as, if engines areused, the weights they take being large, therewill not be a great number upon the road atonce, and the heavy ones making a point ofgiving way to those proceeding at a swifterrate, always keep clear of those travelling withpassengers and light goods.

The mode of causing the carriages to crossfrom one road to the other, is effected in thesame manner as formerly described with theself-acting and engine-planes. A moveablerail, similar to A A', Fig. X., is placed at thejunction of the passing with the main line ofroad; when this moveable rail is thrown backin the position shewn in the drawing, the car-riages proceed along the main line withoutinterruption ; but when put close to the otherrail, as shown by the dotted line in the draw ing,this rail, acting against the projecting ledge onthe wheels of the carriages, prevents them fromcontinuing along the main line, and diverts