Cities of the second class are hereby empowered to construct and maintain street-railway tracks, with such curves, switches, connections, and sidings, and other appurtenances, as may be deemed necessary, upon streets, alleys, and other highways within said municipalities, where street-railway tracks have not been laid, nor has the said municipality authorized the laying of any tracks thereon by any other person or corporation. Said municipal corporations may also construct and maintain such poles, wires, or other overhead, surface, or sub-surface structures, as may be necessary to provide for the operation of cars over said tracks, by electricity or otherwise.