Brick-work is measured and valued by the rod. The contents of a rod of brick-work is 16 feet square; consequently, the superficial rod contains 272.25, or 2724 square feet; but as the quarter has been found troublesome in calculation, 272 superficial feet has been admitted as the standard.

The standard thickness of a brick wall is 1 brick laid lengthwise; therefore, if 272 square feet be multiplied by 13 inches, the result will be 306 cubic feet, or a rod.

Arod of standard brick-work, making the necessary allowance for mortar and waste, will require 4500 bricks; but this quantity is of course ruled by the size of the brick, and the closeness of the joints.

A foot of reduced brick-work requires 17 bricks; a foot superficial of marl facing, laid in Flemish bond, 8 bricks; and a foot superficial of gauged arches, 10 bricks. In paving, a yard will require 82 paving bricks, or 48 stock bricks, or 38 bricks laid flat.

A square of tiling contains 100 superficial feet; and requires of plain tiles, 800 at a six-inch gauge, 700 at a seveninch gauge, or 600 at an eight-inch gauge.

The distances between the respective laths must depend on the pitch of the roof; and one roof may require a 6, 7, and 8 inch gauge. For instance, a kirt roof will require, in the kirt part, a 7 or 8 inch gauge, and in the upper part 6, 61, or 7 inch, the gauge decreasing in the ratio of the angle of elevation.

Α A square of plain tiling will require a bundle of laths, more or less, according to the pitch; with two bushels of lime, one bushel of sand, and a peck of tile-pins.

Laths are sold by the thousand, or bundle; and each bundle is supposed to contain 100 laths, though the exact number depends on the length; the 3 feet containing 5 score, the 4 feet 4 score, the 5 feet 3 score, and so on in proportion.

A square of pan-tiling requires 180 tiles, laid at a teninch gauge; and one bundle, containing 12 laths, ten feet long.

In lime measure, 25 struck bushels, or 100 pecks, make a hundred of lime; 8 gallons, a bushel dry measure; and 268 cubic inches, one gallon.

In measuring sand, 24 heaped, or 30 struck bushels make one load; and 24 cubic feet weighs one ton.

A load of mortar, which ought to contain half a hundred of lime, with a proportionate quantity of sand, is 27 cubic feet.

Excavations of the earth are measured by the number of cubic yards which they contain, therefore, to find the number of cubic yards in a trench, find the solidity of the trench in cubic feet, and divide it by 27, the number of cubic feet in a yard, and the quotient, is the number of cubic yards, and the remainder the number of cubic feet.

For example, the length of a trench is 60 feet, the depth 3 feet, and the breadth 2 feet.

In the horizontal dimensions, if the trench be wider at the top than it is at the bottom, and equal at the ends, take half the sum of the two dimensions for a mean breadth; and if the breadth of one end of the trench exceed that of the other, so as to have two mean breadths, differing from each other, take half the sum of the two added together, as a mean breadth of the whole."

In measuring the footing of a wall, multiply the length and the height of the courses together; then multiply the product by the number of half bricks in the mean breadth, divide the last product by 3, and the quotient is the answer in reduced feet. Instead of measuring the height of the footing, it is customary to allow three inches to each course in height, or multiply the number of courses by 3, which gives the height in inches.

To find the contents in rods of a piece of brick work.

Case 1. If the wall be of the standard thickness, divide the area of the wall by 272, and the quotient is the number of rods, and the remainder the number of feet; but if the wall be either more or less than a brick and a half in thickness, multiply the area of the wall by the number of half bricks, that is, the number of half lengths of a brick; divide the product by 3, which will reduce the wall to the standard thickness of 14 brick, then divide the quotient by 272, and it will give the number of rods, Case II. Divide the number of cubic feet contained in the wall by 306; the quotient will give the number of rods, and the remainder the number of cubic feet.

Case III. Multiply the number of cubic feet in a wall by 8; divide the

product by 9; and the quotient will give the area of the wall at the standard: divide this standard area by 272, and the quotient will give the number of rods; the remainder the reduced feet.

Example. The length of a wall is 60 feet, the height 20 feet, and the thickness equal to the length of three bricks; it is therefore required to know how many rods of brick-work is contained in the said wall ?

By Case I.

60

20

1200

6

3) '7200

272) 2400 (8 rods 224 feet the answer.

2176

224

In the calculation of brick-work, where there are several walls of different thicknesses, it will be quite unnecessary to use the divisors 3 and 272, as will be hereafter shown.

In taking dimensions for workmanship, it is usual to allow the length of each wall on the external side, to compensate for plumbing the angles; but this practice must not be resorted to for labour and materials, as it gives too much quantity in the height of the building or story by two pillars of brick; and in the horizontal dimensions by the thickness of the walls.

In measuring walls, faced with bricks of a superior quality, most surveyors measure the whole as common work, and allow an additional price per rod for the facing, as the superior excellence of the work, and quality' of the bricks may deserve.

Every recess or aperture made in any of the faces must be deducted; but an allowance per foot lineal should be made upon every right angle, whether external or internal, excepting when two external angles may be formed by a brick in breadth, and then only one of them must be allowed.

Gauged arches are sometimes deducted and charged separate; but as the extra price must be allowed in the former case, it will amount to the same thing.

In measuring walls containing chimneys, it is not customary to deduct the flues; but this practice, so far as regards 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, compensate for the loss of time: on the other hand, if the proprietor finds the materials, it is not customary to allow for the trouble of forming the flues, which, consequently, is a loss to the contractor who has engaged by task-work or measure.

If the breast of a chimney project from the face of the wall, and is parallel to it, the best method is, to take the horizontal and vertical dimensions of the face, multiply them together, and multiply the product by the thickness, taken in the thinnest part, without noticing the breast of the chimney; then find the solidity of the breast itself, add these solidities together, and the sum will give the solidity of the wall, including the vacuities, which must be deducted for the real solidity. Nothing more is necessary to be said of the shaft, than to take its dimensions in height, breadth, and thickness, in order to ascertain its solidity.

If a chimney be placed at an angle, with the face of the breast intersecting the two sides of the wall, the breast of the chimney must be considered a triangular prism. 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 the triangle on the floor, included between the front and these lines, will be equal to the triangle on which the chimney stands, and, consequently, equal to the area of the base. To attain the area of the triangular base, the dimensions may be taken in three various ways, almost equally easy; one of which is, to take the extent of the base, which is the horizontal dimension of the breast, and multiply it by half of the perpendicular; or multiply the whole perpendicular by half the base but, as this calculation would, in cases of odd numbers, run somewhat long, a more preferable method is, to multiply the whole base by the whole perpendicular, and take half of the product, which will give the area on which the chimney stands; and which, multiplied by the height, gives the solid contents of the chimney. From this contents is to be deducted the vacuity for the fire-place.

A row of plain tiles, laid edge to edge, with their broad surfaces parallel to the termination of a wall, so as to project over the wall at right angles to the vertical surface, is called single plain tile creasing; and two rows, laid one above the other, the one row breaking the joints of the other, are called double plain tile creasing.

Over the plain tile creasing a row of bricks is placed on edge, with their length in the thickness of the wall, and are called a barge course, or cope.

The bricks in gables, which terminate with plain tile creasing coped with bricks, in order to form the sloping bed for the plain tile creasing, must be cut, and the sloping of the bricks thus, is called cut splay.

Plain tile creasing and cut splay are charged by the foot run; and the latter is sometimes charged by the superficial foot.

A brick wall built in pannels between timber quarters is called brick nogging; and is generally measured by the yard square, the quarters and nogging pieces being included in the measure.

Pointing is the filling up the joints of the bricks after the walls are built. It consists in raking out some of the mortar from the joints, and filling them again with blue mortar, and in one kind of pointing, the courses are simply