This section is from the book "The Building Trades Pocketbook", by International Correspondence Schools. Also available from Amazon: Building Trades Pocketbook: a Handy Manual of reference on Building Construction.
Stone masonry is usually measured by the perch; in some sections of the country, however, measurement by the cord is preferred, but the best method (as being invariable) is by the cubic yard. In estimating by the perch, it should be stated how much the perch is taken at, whether 24 3/4 or 25 cu. ft. Note should also be made in regard to deduction for openings, as in most localities it is not customary to deduct those under a certain size, and corners are usually measured twice.
Rough stone from the quarry is usually sold under two classifications, namely, rubble and dimension stone. Hubble consists of pieces of irregular size, such as are most easily obtained from the quarry, up to 12 in. in thickness by 24 in.
Bubble masonry and stone backing are generally figured by the perch or the cubic yard. Dimension-stone footings are measured by the square foot unless they are built of large irregular stone, in which case they are measured the same as rubble. Ashlar work is always figured by the superficial foot; openings are usually deducted and the jambs are measured in with the face work. Flagging and slabs of all kinds, such as hearths, treads for steps, etc., are measured by the square foot; sills, lintels, moldings, belt courses, and cornices, by the lineal foot, and irregular pieces are generally figured by the cubic foot. All carved work is done at an agreed price by the piece.