121. At the quarry, stone is divided into two classes: dimension stone and rubble. The first consists of those pieces which are quarried in regular shapes, and to a fixed size, usually 24 inches square or more in area, and over 8 inches thick. This class of stone is generally sold by the cubic foot, and costs about three or four times as much as rubble.

Rubble includes pieces of various sizes and shapes which form the waste in quarrying the larger stones. It is suitable for work in which the courses are 12 inches or less in height. and the stones are not over 24 inches long. Generally speaking, all stone not quarried to a certain size may be termed rubble. It is usually sold by the carload, or in small quantities by the perch, and in some places by the ton.

122. The methods of measuring stone are very unsatisfactory, owing to the great difference in practice in various parts of the country. Dimension stone footings are generally measured by the square foot. If built of large rubble, or irregular stones, the footings are usually Figured in with the walls, with allowance for the extra width. Rubble is usually measured by the perch, which, unfortunately, varies from 16 to 25 cubic feet, being 24 3/4 cubic feet in the Eastern states, 16 2/3 feet by custom in Colorado, and 22 to 25 cubic feet in various other places. A necessary precaution, to prevent disputes, when work is to be measured by the perch, is to agree on the number of cubic feet in a perch, and also in regard to deductions for openings. If this is not done, the custom of the particular locality would probably govern in case of disagreement. In some places, rubble work is measured by the cubic yard of 27 cubic feet, or by the cord of 128 cubic feet. Stone backing is commonly Figured the same as rubble.

Ashlar masonry is almost invariably measured by the square foot, the cost depending on the kind of work and size of the stones. It is usual to deduct openings in ashlar work; when the width of the jambs of windows is more than the depth of the ashlar, the jambs are usually measured in with the face work. Flagging and all thin pieces or slabs are Figured by the square foot.

Moldings, belt courses, and cornices are usually measured by the lineal foot, but if the shapes are not regular they are Figured by the cubic foot. All carved work is estimated by the piece.

Trimmings are sometimes Figured by the cubic foot, the price varying with the amount of labor required in dressing. Probably the most accurate way of Figuring this class of work is to first estimate the value of the rough stone, and then that of the labor involved in the different classes of work, the resulting prices being per lineal foot. This method is the one usually employed in Figuring granite work.