Abstract.
The next thing to be done is to affix the price of the common measure to each of the above species of work, and from this, to calculate the quantity of each; then insert the several sums in a bill, as follows: Rods. Feet. d O 73i* Superficial of place-brick work reduced t 3 8 to the standard at £12. 15s. per rod 3 24'2 Superficial of gray-stock work reduced l 56 8 0 to the standard at £14. 10:a per rod O 595 Feet lineal of quoins in apertures at Id I. 2 9 7 per foot O 531 Superficial of rubbed and gauged f 8 0 6 at 3s. per foot 0 571/ Superficial of marl facing at 6d per foot 14 7 4i £S4 13 101 * not noticed in the calculation.
In the foregoing admeasurement, the quoins are valued by • the foot lineal, in addition, and the method of making out the contents is different from that commonly used ; but though the allowance is strictly just, and the practice shorter and less liable to mistake than that in common use; that there should The above contents are abstracted by inserting each area in a separate column, according to the number of half bricks it is thick.
In the following abstract, the several parts of each column are collected : the sum or amount is multiplied by the number of halfbricks, and the product divided by 3; then the positive quantities are added together, and the negative ones added together, their difference is the real quantity in reduced feet, by dividing which by 21'2, the answer will be obtained in rods Instead of dividing by 3, a's in the above abstract, it would be easier to add the products of the half brickwork, both for the walling and for the deductions, and subtract the deductions from the walling ; divide the difference by 3, and the quotient by 272, should it be found neces sary.
The other parts of the above abstracts are as in the pre ceding, and are, therefore, not again repeated.
A wall common to two houses, the properties of different persons, is termed a pang wall; but if a building stands insulated, the walls which join the entrance to the rear front are called flank walls. Chimneys are generally carried up, either in party walls, flank walls, or partition walls, and some times in all of them ; hut never, or very seldom, in the front or rear walls. When the walls which contain the chimneys are thin, it becomes necessary to furm a projection of sufficient breadth and depth, for the reception of the flues, or as many of them as can be collected into one stack. This projection
is generally a rectangular prism, showing three vertical sides, and is termed the or breast of the chimney.
The method of measuring the solid contents of every part of a building, is to reduce all the parts into rectangular prisms, and then find the solid contents of each prism. It frequently happens that walls consist of a cluster of prisms, which may be differently divided, in order to separate them. All apertures or cavities of any consequence, ought to be deducted from the measure, whether the proprietor or the contractor find the materials; but as every return or termi nation requires more trouble than a continued wall, an allow ance ought to be made in lineal measure, upon every foot of angles, or terminations, as before mentioned, for the trouble of plumbing, levelling, and straighting. It is true, that a great length of wall requires several intermediate phimbings, but then, as they are only regulated upon the face, the trouble is small in comparison to what is required in a vertical termi nation, or a deflection of the wall from its course, by another return wall at an angle with it ; and as these plumbings may be made at regular distances, the parts of the wall may be said to be uniformly built, and the same in all equal lengths of walls, and the time proportional to the quantity under the same circumstances of height and thickness, and therefore the area or solidity is a fair ratio of the price : and farther it is evident, that the greater the number of apertures or vacui ties, in the same length of wall, the more trouble will they occasion the workmen, since more time is required to form the sides of the apertures, or the boundaries of the vacuities. In this case, therefore, the time of completing a wall of given dimensions, even with the same quality of work, depends upon the number of quoins that are to be built, and consequently cannot be determined by the solidity of the wall, but jointly by this measure and the lineal quantity of angles ; for the solidity is not as the time, when the number of quoins are increased, and consequently the price not as the time ; but the price may be made up by the increase of the angles.