The buff-colored tile is made of nearly pure fire-clay, and it is slightly lighter in weight than the red tile.
The black tile is made by washing it over before burning with manganese dissolved in water, which, in the process of burning, is converted into a perfectly durable coating of great hardness.
The patterns usually employed with us for roofing-tiles are of several kinds ; the large diamond, the small diamond shingle, round corner, round end, gothic, etc.
The large diamond tiles are 14 inches, the length of the dia mond, and inches in the width ; 250 cover one hundred surface feet, 10 by 10 feet, called a " square," and weigh 650 pounds.
They are fastened with two sixpenny galvanized iron or tinned nails. This kind of tile is used more than the other styles, as it is lighter in weight, and less in cost.
The small diamond, 6 by 10 inches, requires 500 to cover a square, and it weighs 600 pounds. It is nailed with five-penny nails, and is used more especially for towers, porches, dormer windows, and in side panels, for ornamental purposes.
The shingle tiles are the plain, flat tiles described in the com mencement of this chapter ; they are three-eighths of an inch thick, have two counter-sunk nail-holes, and are made of any size, not exceeding 6 by 12 inches ; they can be had for round or square towers, dormer windows, etc., and the points are sometimes cut semicircular, octagonal, gothic, or pointed.
They have been largely used in the Eastern States, and on some expensive buildings for roofing and side ornamentation, as at the State capitol at Albany, New York, on which building they are wired to iron ribs.
These tiles are generally laid about 5 inches exposed to the weather, which requires about 480 for a square, weight being Ioo pounds.
The pantiles measure 12 inches in length by inches in width at one end, and at the other, and if they are lapped inches on the roof, 35o will be required for a square, which will weigh 85o pounds.
This kind of tile makes a strong roof cover, and can be walked upon without danger of breaking, and is especially suit able for workshops and factories ; it is sometimes made with lugs to hang on to ribs, the use of nails being therefore avoided, which are liable to rust away where much bituminous coal is used. It is also made with nail-holes to secure it to the sheath ing. Brick-making is now mostly done by machinery, and there is not the least doubt but that tiles of all kinds will also be generally so made both in this country and in Europe.
The roofing-tiles which have just been described are made by machinery by the firm of J. C. Ewart & Co , Akron, Ohio.
The machines which they employ were patented by Mr. C. J. Merrill about twenty-five years ago.
Roofing-tiles are now often made by running the clay through a stiff-clay machine, the blanks being formed thereby, and then pressing the blanks upon a hand or power press such as is made by C. W. Raymond & Co., of Dayton, Ohio.