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.

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.