To ensure that the stalk shall fall in a narrow compass, it will be desirable to fix three guy ropes from the top, equally divided round the circle, and made fast at a distance from the base of the shaft at least equal to half the height. Openings should be cut in the brickwork of the base on opposite sides, and 9-in. by 9-in. studs inserted, about 4ft. long, between 9-in. by 3-in. plates running through the thickness. Before making the openings, 9-in. by 3-in. raking shores both ways should he fixed at each corner of the base. Two openings in each side, with a brick pier left between, would, in the writer's opinion, be required; and when this is done, if there is no sign of cracking or settlement, and the studs are taking a good bearing, the intervening pier in centre of each side may be cut away. Everything must be done systematically, working at opposite sides in turn. Waste wood should then be piled round the base in sufficient quantity to ensure that the wood studs will be burnt through, and lighted at several points. A couple of look-out men during the operations should be posted sufficiently far off to command a view of the chimney from two directions at right angles, and near enough to warn the men if any signs of premature falling were to occur.

Local circumstances and the construction and condition of the chimney stalk may render some varia tion on the above method desirable. A cheaper method, and one that would probably be satisfactory in the hands of an expert in explosives, would be to explod a small charge of dynamite in the bottom of the shall, or to bore holes round the base and insert charges of gunpowder, to be fired simultaneously.