For boring holes about 1/2 in. or 3/4in. diameter at any place in an ordinary brick wall, an old twist-bit used as a boring to »1 may be made to serve the purpose: a piece of steel tube, such as cycles are made with, will, if jagged at the end, answer very well. These tools are only suitable where the bricks are fairly soft; with hard bricks it is quicker and easier to make holes with a chisel and hammer in the usual manner. Holes may be very quickly drilled in brick or stone walls by making the cutting end of the drill in the form of a cross with four cutting edges. The drill is held in one hand and rotated while being struck with a hammer. When the holes are required to be deep, a projection may be made n the outer end, by which it can be knocked out of the hole quickly. The cutting end should be larger than the shank, so as to allow for clearance, and the shank should be sufficiently long to allow a hammer to be used for knocking it out of a deep hole.