Brickwork is estimated at the rate of a number of bricks in thickness, estimating a brick at 4 inches thick. The dimensions of a building are usually taken by measuring half round on the outside, and half round on the inside; the sum of these two gives the compass of the wall,-to be multiplied by the height, for the content of the materials. Chimneys are by some measured as if they were solid, deducting only the. vacuity from the hearth to the mantel, on account of the trouble of them. And by Others they are girt or measured round for their breadth, and the height of the story is their height, taking the depth of the jambs for their thickness. And in this case, no deduction is made for the vacuity from the floor to the mantel-tree, because of the gathering of the breast and wings, to make room for the hearth in the next story. To measure the chimney shafts, which appear above the building, gird them about with a line for the breadth, to multiply by their height. And account their thickness half a brick more than it really is, in consideration of the plastering and scaffolding. All windows, doors, etc, are to be deducted out of the contents of the walls in which they are placed. But this deduction is made only with regard to materials; for the whole measure is taken for workmanship, and that all outside measure too, namely, measuring quite round the outside of the building, being in consideration of the trouble of the returns or angles. There are also some other allowances, such as double measure for feathered gable ends, etc.

Example.-The end wall of a house is 28 feet long, and 37 feel high to the eaves: 15 feet high is four bricks or 1G inches thick, other 12 feet is three bricks or 12 inches thick, and the remaining 10 feet is two bricks or 8 inches thick; above which is a triangular gable 12 feet high and one brick or 4 inches in thickness. What number of bricks are there in the said wall? Ans. 25,620.

 thickness. 98 X 15 = 420 X 4 = 1680 :contents of 1st story. 28 X 12 330 X 3 = 1008 " " 2d " 28 X 10 = 280 X •J = 560 " " 3d II 12÷2 = 6 X 28 = 168 X 1 = 168 " ii gab ". 3416 square feet area of whole wall. 7½ bricks to square foot. 23,912 By the table 1,708 3000 suprfi. ". = 22,500 bricks. 400 " " 3,000 " Answer,- 25,,620 bricks. 10 " " 75 " 6 II " 45 " 3416 " " = 25,020 bricks

A Table by which to ascertain the. number of Bricks necessary to construct any Piece of Building, from a four-inch Wall to twenty-four inches in Thickness.

The utility of the Table (on next page) can be seen by the following Example. Required the number of bricks to build a wall of 12 inches thickness, and containing an area of 6,137 square feet.

 Square feet 1000 22,500 bricks-See table. X 6 6 NOTE. - 7½ bricks, equal one superficial foot. 6000 = 135 000 400 - 9,000 30 = 075 7 = 158 6,437 = 144,833 bricks.
 Superficial feel of Wall. Number of Bricks to Thickness of 4-inch 8inch. 12-inch. 16-inch. 20-iuch. | 24-inch. 1 8 15 23 30 38 45 2 15 30 45 60 75 00 3 23 45 68 90 113 135 4 30 60 90 120 150 180 5 38 75 113 150 188 225 6 45 90 135 180 225 270 7 53 105 158 210 263 315 8 60 120 180 210 300 360 9 68 135 203 270 338 405 10 75 150 225 300 375 450 20 150 300 450 600 750 900 30 225 450 675 900 1125 1350 40 300 600 900 1200 1500 1800 50 375 750 1125 1500 1875 2250 60 450 900 1350 1800 2250 2700 70 525 1050 1575 2100 2625 3150 80 600 1200 1800 2400 3000 3600 90 675 1350 2025 2700 3375 4050 100 750 1500 2250 3000 3750 4500 200 1500 3000 4500 6000 7500 9000 300 2250 4500 6750 9000 11250 13500 400 3000 6000 9000 12000 15000 18000 500 3750 7500 11250 15000 18750 22500 600 4500 9000 13500 18000 22500 27000 700 5250 10500 15750 21000 26250 31500 800 6000 12000 18000 24000 30000 36000 900 6750 13500 20250 27000 33750 40500 1000 7500 15000 22500 30000 37500 45000