sity of considering the subject of heating coincidently with the construction of the houses.
The Flue System.—The simplest method of heating is by means of a furnace and brick flue. Every skilled bricklayer knows how to heat a house by this method, but it is well that those who have to pay and take the consequences should know something about it also. It is necessary, in the first place, to provide a sufficiently capacious stoke-hole at the end of the house, or, in the case of a lean-to, behind the back wall. This must be sunk below the level, and there must be a decided rise from the fire to the flue, to enable the draught to overcome the check which the heat encounters in taking the horizontal course of the flue. The simplest arrangement in the case of a lean-to is to take the flue along the front of the house, rising slightly all the way, and terminating in a chimney at the other end. In the case of a span-roofed house it will be desirable to take the flue round the house, rising gently all the way, and terminating in a chimney over the furnace. It will be understood that the necessity of a continuous rise of the flue renders it desirable to place the furnace low enough in the first instance. It is desirable to detach the flue at every point from the floor of the house by means of piers, to allow of a circulation of air around the whole exterior of the flue, and promote a consequent equable distribution of the heat. A small flue of four-inch or six-inch drain-pipes, well cemented at the joints, may suffice for a small house, but what we should consider a good flue would be two feet high and one foot wide, the sides of brickwork, and the top and bottom red foot tiles or slates. A serviceable flue, however, may be made eight inches wide and sixteen inches deep, and in any case the depth should, exceed the width, or it will not draw well. It is a good plan to plaster the flue on the outside, to prevent the escape of smoke, but this is not needed if it is well built, and it certainly does slightly check the communication of heat to the house for the first hour or so after the fire is lighted. A trough for water on the top of the flue should be provided. In some districts tiles, with sunken surfaces, may be obtained for this purpose, but a cistern of zinc or iron is everywhere obtainable. But whoever can construct a flue will find no difficulty in securing an evaporation of water from the top of it. The kind of fuel to be burned will, in some degree, determine the size and material of the flue, for the
