HOW IT WORKS.

number is that of the lever itself; the others, called leads, refer to levers which must be pulled before that particular lever can be released.

Fig. 97. —Model signal equipment in a signalling school. (By permission of the "G.W.R. Magazine").

POINTS.

Mention was made, in connection with the lever, of points. Before going further we will glance at the action of these devices for enabling a train to run from one set of rails to another. Figs. 98 and 99 show the points at a simple

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