It is likewise evident, that in building quoins, while the workmen continue at the same rate of work, the lineal quantity is in the same ratio as the time, and therefore this lineal measure is a fair representation of the value of the work. In carrying up a wall of the same horizontal length, N% here there are no vacuities, the quantity of work performed by the same number of bricklayers is equal in equal times, but the work requires an additional number of labourers as the height increases, to supply the materials; in this case also, the quantity of surface is a fair representation of the value of the work, in respect of the bricklayers, but an additional sum must be added as the work proceeds, and this increase would be the terms of an arithmetical progression ; for suppose the materials at the foot of the seallidd, and the scaffolding erected at regular heights; now it is evident, that whatever time the labourer requires to mount the first scaffold, he would require a time double, triple, quadruple, the first, &c., to mount the second, third, fourth scaffold, &e.: the sum of all these times is the whole time. There should also be a uniform increase of price for the use of scaffolding, as well as for an number of labourers, as the work is carried upwards. Front the aggregate of these circumstances, it is evident, that the value of the labour, with respect to the bricklayers, may be fairly estimated by the quantity of surface, of equal thickness, but an increase of price must be allowed for labourers and scaffolding.
To measure and value party walls, flan: walls, and par tition walls with flues.—Find the cubical contents of the whole, or each part of the wall, in feet, according to its figure, or the figures into which it may be resolved ; deduct the vacuities, nmItiply the remainder by 8, and divide the pro duct by 9, and the work will be reduced to the standard ; then take the lineal measure of all the quoins, whether exter nal or internal, the proper rate being affixed to each common measure, and it will give the value of the whole.
In measuring walls containing chimneys, it is not cus tomary to deduct the fines ; but this practice with regard to the materials, is unjust, though perhaps, by taking the labour and materials together, the overcharge, with respect to the quantity of bricks and mortar, may, in some degree, com pensate for the loss of time; on the other hand, should the proprietor find the materials, it is not to allow for the trouble of forming the flues, which is therefore a loss to the contractor, or to the workman who engages to execute his part by measure or task-work.
With regard to the allowance for the lineal measure of quoins. we regret to observe, that the practice is not general, and, so far as we know, has only as yet taken place in outside and inside splays, and the angles of groins : we admit that every innovation, not founded upon reason, ought to be resisted ; but as we are convinced of the justice of this mode, we have here ventured to introduce this as a general practice, which ought to be followed in every ease, whether the quoins be vertical, or horizontal, or curved ; and an appropriate price should be affixed to each species of quoins, whether external or internal, right-angled or oblique, curves or right lines, as the trouble is greater in external than in internal angles, greater in oblique than in right angles, greater in curved quoins than in straight ones, and still greater in groins, where the angles are continually- varying, than in curves where the angles same throughout.
If the brick-work of the footing of a wall project equally on each side, and if the bricks be of the same kind as the wall above, take the height of the wall from the bottom of the footing, as high as it goes of the same thickness ; multiply that by the length and the thickness, and reserve this solidity ; then multiply the length of the wall, the height of the footing, and its projection with the addition of half a brick, will give the solidity of the footing; add these two solidities together, and the sum will be the solidity of the wall, from which deduct the vacuities, and the remainder will be the quantity of solid work.
If the breast of a chimney project from the surface of the wall, and be parallel thereto, the best method is to take the horizontal and vertical dimension of the face, multiply these together, and the product by the thickness taken in the thin nest part, taking no notice of the breast of the chimney ; then find the solidity of the breast. itself; add these solidifies together, and the sum will give the solidity of the wall, including the vacuities, which 'mist be deducted for the real solidity ; after taking the dimensions for the quantity of brick-work, the lineal quantity of angles should be taken, and entered in the Dimension Book.
Nothing more is necessary to be said of the shaft, than to take its dimension in height, and horizontally in breadth and thickness, in order to ascertain the solidity ; and then take the lineal quantity of angles, and enter them all in the Di. mension Book.
If a chimney is placed in the angle, with the face of the breast intersecting the two sides of the wall, the breast of the chimney must be considered as a triangular prism ; to find the solidity, therefore, multiply the area of the base by the height of the surface of the front or breast, and the pro duct is the solidity.
To take the dimensions : from the intersections of the front of the breast into the two adjacent walls, draw two lines on the floor parallel to each adjacent wall, then will the triangle on the floor, included between the front and these lines, be equal to the triangular base of the chimney. In order to obtain the area of the triangular base, the dimensions may be taken in three various ways, almost equally easy ; but as con venient a method is to take the extent of the base, which is the horizontal dimension of the breast., and multiply that by half the perpendicular ; or, multiply the whole perpendicular by half the base, liar the area of the surface on which the prism stands ; but as fractions arise by the halving of odd numbers, it would be better in such cases to multiply the whole per pendicular by the whole base, and half the product will give the area of the prismatic base, which is that of the chimney breast.