This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol2", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
This, if executed in the district in which the stone is found, is usually measured in accordance with local custom, which varies considerably. In London it is measured per yard super. up to and including 18 inches thick, stating the thickness, and per yard cube over 18 inches thick. Fully describe the coursing. Facings, if in the same kind of stone, are measured per foot super. as extra on the walling, fully describing the coursing, pointing, and how face of stone is finished. Arches are numbered and fully described, including cuttings, as extra on facings, and the dimensions (face, soffit, and span) given. Dressings, if in the same kind of stone, are measured as extra on facings, and fully described, stating that they are in "jambs" or "quoins," etc., as the case may be.
Kentish rag or other rubble facing to brick backing is measured per foot super. as extra on brickwork, and fully described, and the average thickness stated. State the size of bond stones, and their number per yard super.