“Initially wood-framed in the 18th and 19th centuries, skylights became even more popular in metal construction with the advent of sheet-metal shops during the Victorian era. Virtually every urban row house of the late-19th and early-20th centuries relied upon a metal-framed skylight to illuminate its enclosed stairwell. More elaborate dwellings of the era showed a fondness for the Roof Lantern, in which the humble ceiling-window design of the skylight is elaborated into a miniature glass-paneled conservatory-style roof cupola or tower”