Picturesque, polychromatic slate designs in Canadian roofing installation were most often identified with the Second Empire mode and yet variously cut slates of uniform colour were the norm for Canadian mansards. The predominant use of all black slating was a natural outcome of supply. The chapter on slate sources indicates that until 1900, 80 percent of the Canadian market was provided from the black slate belt of the Eastern Townships. Government House in Toronto (1868-70) roofed with slate from Quebec’s Melbourne, quarry, developed in the 1860s, was an example of a high-style Second Empire residence using continuous black slating. This manner of applying slate was in greater evidence in multiple housing, schools and religious institutions вЂ” buildings that had adopted the mansard idiom as a practical way of providing additional living space. Heavy concentrations of slating have been recorded on mansarded row housing throughout Montreal on such streets as Cherrier and St. Hubert. Maison Mere Villa Maria (1878), College du Vieux Montreal (1888), and other mansarded Roman Catholic convents and colleges across Canada again illustrated the widespread use of black slate roofing. The High Victorian principle of polychrome which characterized the slate roofs of so many Gothic Revival and Second Empire buildings in Canada endured from the late 1850s to the late 1880s. Anchored in English reinterpretations of the Gothic Revival and a return to continental and particularly Italian sources, the colorful slate patterns which emulated the geometric mosaics of medieval brick and marble were seen at their jagged Gothic best in the churches of Ontario. The colour banding of variously cut slate equally typical of High Victorian Gothic was continued in the Second Empire mode, where love of the curved form produced some of the most delightfully picturesque, polychrome slate designs in Canadian domestic architecture. Polychrome slating also crept into other styles, such as the 1886-87 renovations of the Neoclassic 1852-53 Brantford County Court House. Architectural taste, however, ultimately tired of the rich slate designs that were dubbed oil-cloth or calico patterns. The undercurrent of uniformly coloured slating that marked the diffused Second Empire mode grew stronger in the late 1870s and early 1880s.
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