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.
There are two principal methods of measuring stonework. One is to measure the stone and labour together per foot cube, splitting it up into parts on which the labours are similar, and fully describing them and giving sketches of the more ornate parts.
The other method is to measure the stone per foot cube, and measure all the labours on it separately per foot run or per fool super. according to their width or girth. Under this system great uncertainty formerly prevailed as to what extent preliminary labours had been measured, as there was no uniformity of practice in this respect.
In modern practice the second method has been modified to the extent of eliminating the preparatory labours, so that all finished faces include these; it has also become customary to include plain beds and joints with the cube stone, and hoistings and setting also. Whichever system is adopted, it should be clearly stated at the end of the Preamble.
The modes of measurement will be given here which are applicable under the system in which the following clause occurs in the Preamble to the Mason's Bill: "All finished surfaces to include preparatory labours," but first of all the following exceptions must be particularly noticed:-
2nd. Plain Face must be measured to both faces of stone in tracery heads when these are measured in detail; but this is rarely done now.
With the above exceptions, whenever a superior labour is measured over any portion of a face previously measured, deduct the previous labour on that portion.
"Rough Sunk Work," although really a preparatory face, is always measured where it occurs, notwithstanding the note as to preparatory faces being included; and for the reason, that in a given quantity of "sunk face," rough sunk work may or may not be a necessary preliminary, and so if it were not measured there would be two possible values to "sunk face."
The London practice is to measure this net, and a note to that effect must be inserted in the Preamble. It is measured per foot cube, the net size of the smallest cube out of which the stone could be cut. Even in the case of triangular stones where a saving might be effected by cutting two pieces out of one block it is not usual to take it so, but if it is done it must be clearly stated. Include and describe the hoisting and sitting up to 40 feet high with the stone. Keep any above that height separate, and divide it into heights of 20 feet. Keep stone in scantling lengths (this varies with the kind of stone, for Portland it is 6 feet) separate.
When any labour cannot be worked in a length right through the stone it is kept separate and described as stopped. A rebate, however, is not described as stopped on account of the angle in it, unless the rebate finish with a return end.
To be kept separate, and described as such.
Labours in Short Lenghts, say 9 inches and under, to be kept separate, and described as such.
These are numbered and described. In the case of cramps, state their weight, and include the sinkings or mortices and running with lead.
Sawing, although never measured now, must be explained, in order that the method of measuring the labours to backs, beds, and joints may be understood. In sawing a long block into two or more stones, each cut provides two sawn faces, and the labour to each of those faces is known as "half-sawing."
The back of a stone may be merely the quarry face, or it may be sawn; and in either case it may require a little extra labour on it. This is described as "labour to back," and includes the half-sawing (if any).
The top and bottom of the stone, as it is placed in the wall, with stones or brickwork above and below it, will, in addition to "half sawing," require a little extra labour to be expended on it in order to produce an even bed, and the entire labour, including the half-sawing, is called "half-bed." A similar labour to the end is called half-joint. These labours are measured the full size of the top, bottom, and end faces of the true cube. Beds and joints are billed together, and if each face is measured, the amount, must be divided by 2 on the Abstract, and billed as "plain beds and joints"; or, in the case of a stone in the middle of a wall, one bed and one joint may be measured instead of two half-beds and two half-joints. Note that in the case of granite the beds and joints are "all measured "; that is, a full bed or joint is measured to each face instead of a half-bed or joint as to other stones.
Sunk Beds and Joints are measured per foot super. to any bed or joint "out of square," or sunk below the general surface of a true cube. Notice that this is all measured; that is to say, that each surface so measured is a sunk bed or joint, and not a sunk half-bed or joint.
Measure per foot super., and "all measured." There are convex or concave beds and joints, such as to the extrados or soffite of a relieving arch.
Measure per foot super., and "all measured," to joints which are sunk below the surface of a circular face, such as a rebate for frame in the soffite of an arch. If stopped, keep it separate.