Almost all of the finest buildings in our cities are disfigured by grimy and black streaks leading down from the vertical joints in the stone cornices or projecting mouldings. This could and should be prevented by the use of metal or other flashings for large projections, and raised joints for the smaller ones. In the use of terra-cotta this is imperative ; for careless workmen will often neglect to fill in the work properly when it is being placed in its permanent position. Water and ice will then in due course cause trouble.
The color of terra-cotta is a frequent cause of contention. It ought not to be. Absolute uniformity of color is beyond the possibility of manufacture. It should be remembered that the tone of color is governed by the chemical constituents of the clay, and the shade of color is governed by the degree of heat involved in burning—a few degrees more causing the darker shades, or a few degrees less producing the lighter shades. The regulation of the heat of a kiln of burned clay (during the process of firing) within certain limits is at present beyond the ability of the most experienced of our clay workers.
Hence it is unfair to ask it of them. If the question of shade of color is important to a certain design, as we have said, why not utilize the painter? He has a recognized field in the decoration of wood and iron. Is there any sound reason why he should not also decorate the terra-cotta work? Mechani cally there is none, for a coat of lead paint will last much longer upon terra-cotta than upon any other building material ever used, not excepting wood or iron.
A study of the relations of terra-cotta to architectural design, founded upon a practical knowledge of this material, will surely enable our architects to produce an ideal brick and terra-cotta structure, which shall as truly make its mark in our day as did the Certosa of Pavia, the Church of St. Rustico at Caravaggio, the Cathedral of Cremona, and other buildings of Northern Italy, centuries ago.