Polychrome slating associated with the High Victorian Gothic mode was undoubtedly a stimulus in the first large-scale commercial exploitation of slate in the United States in the late 1850s. American design books, at any rate, were not long in linking the availability of coloured slate with suggestions for roof patterns in varying tints. In 1857 architect Calvert Vaux, a former colleague of the now deceased Downing, wrote in Villas and Cottages: Lately, new American quarries, supplying slate of different colours, have been opened in various parts of the country and worked with success. The slate that come from the Eagle quarries in Vermont is of two tints: the one a rich purple-gray, the other a delicate green. This slate, when arranged by a roofing company on a roof in stripes or patterns, so that the colours are equally represented, has a very agreeable effect, and one that is far superior to that produced by any shingle or metal roof.
Similar endorsations of two or more slate colours for the same roof were made by Samuel Sloan, Hudson Holly and other purveyors of Gothic home designs. The elaborate “picturesque Gothic cottage” illustrated in these popular publications was rarely duplicated in Canada. However, the L-shaped house with the increased vertical proportions of the last half of the 19lh century often employed polychrome slate roofing effects to complement or replace mural colour arrangements.
Appropriately enough, because it was in ecclesiastical architecture that the High Victorian Gothic had its most enduring influence in Canada, churches, more than any other single type of building, illustrate the polychrome slate
fashion. In her study Gothic Revival in Canadian Architecture, Mathilde Brosscau documented the preponderance of High Victorian religious architecture in Ontario, a conclusion corroborated by CIHB. Its printout on slate roofing indicated more Ontario churches with polychromatic slate roofing that churches in any other province of Canada. Ontario’s architects obtained commissions from various denominations so the practice of polychrome slating crossed religious and regional boundaries. St. Michael’s Roman Catholic Church (1845-66) and its neighbour the Metropolitan Methodist Church (1872) in Toronto provide striking examples of the diversity of patterns that were executed in slate. Delicate slate borders and decorative crosses embellish St. Michael’s roof while spiky elongated diamonds vigorously zigzag their way across the main roof of the Methodist Church. The ecclesiastical icons of the former example appear rarely in slate roofing although the “Cross Patton” of the 1880 Central Presbyterian Church in Cambridge provides another charming exception. The diamond-slate pattern of the Toronto Methodist example was ubiquitous and various, forming simple horizontal rows of large or small diamonds, or diamond rows enclosed with parallel lines or courses of round slates.