A circle is the easiest form of track to make. In laying out a circle or any sort of curved track, the outside rail must necessarily be made longer than the inside one.
The oval shape is a very good form to give the track in a great many cases, especially where it is desirable for the car to have a longer path than that afforded by a circle.
Fig. 275.—Details of the Base of the Cross-over.
In order to make a figure-eight out of the track, a crossing, or "cross-over," as it is sometimes called, will be required. This is shown in Figure 275. A cross-over permits two tracks to cross each other without interference. It consists of a wooden base, eight inches square and three-eighths of an inch thick. Four saw-cuts, each pair exactly parallel, and two inches apart, are made at right angles to each other across the top surface of the base, as shown in the illustration.
The track used on the cross-over is semi-hard hoop-brass, one-half of an inch wide and of the same gauge as the steel track. The brass is more easily bent than the steel and is used for that reason, it being practically impossible to bend the steel track at right angles without snapping it.
Four pieces of the brass, each five inches long, are bent at right angles exactly in the center. Four short pieces, each one and one-half inches long, will also be required.
Fig. 276.—The Completed Cross-over.
The cross-over is assembled as shown in Figure 276. The strips marked D are strips of very thin sheet-brass or copper. The purpose of these strips is to connect the ends of the track on the cross-over to the ends of the track forming the figure-eight so that the cross-over will not be a "dead" section, that is, a section of track where the car cannot get any current.