Besides the carriage-way, the Italianate facade of the Prince of Wales's is interesting in that its arches contain, not only pedestrian entrances to the stalls boxes and the pit circle, but also two shops, one of which led to extensive supper-rooms. The lions' heads above the lamps on the pilasters were in fact ventilation apertures. The architect was at pains to provide better ventilation than hitherto by using an elaborate system of air shafts converging above the central chandelier. Even the complicated stage machinery was much improved; it was now driven by an engine and a boiler, situated on a level below the understage machinery-floor. The old system of visible footlights was replaced by an enamelled-iron box-trough set into the stage floor, a novelty which subsequently became the norm.

In:  Glasstone, Victor: Victorian and Edwardian Theatres: An Architectural and Social Survey. Harvard 1975 p. 43

Author: Victor Glasstone