4699. Barker, G. Feb. 25. Elevated railways and tramways.-Overhead rail. ways, elevated tracks, or bridges have side girders or trusses outwardly inclined from below upwards and connected by a horizontal member at or near their lower parts with lines or tracks for vehicles at or near the inward angles formed by the inclined sides. Fig. 1 shows a construction with plate girders a and side stiffeners o, but the girders may be built up of tension and compression members and the sides maybe extended upwardly and connected by bracing over the passage way. Rails or troughs &c. for the vehicle may be carried by longitudinal or cross sleepers, or parts of the structure may serve for their direct support. For a double line of rails, the structure may consist of two splayed troughs side by side, or a single wide trough-like construction.