Large furnaces are sometimes seen, with flues of brickwork. In view of the foregoing remarks, it will be obvious that these tend to large fires and a rapid combustion, and hence must be classed as undesirable.
Brick Stoves.—Developing from “drum” furnaces, another type comes into existence. In principle it consists of an enclosed brick furnace, with feeding door, and a low conical dome surmounted by an adjustable cap or spark-arrester. The rate of combustion can be influenced by a suitable movement of the cap, which is operated by a screw. This type of furnace has been installed on several estates by the engineering department of Messrs. Harrisons and Crosfield, and is understood to give satisfaction.
Pataling Type.—With the exception of the “Third Mile” type already mentioned, all the furnaces described are open to a strong objection, in that the coolies have to enter a room, usually filled with hot smoke, in order to attend to the fires. The mere opening of the door of the building is sufficient to fan most fires into a blaze and to raise sparks. Apart from these points, it is natural for coolies to avoid entering too often, with the result that they generally stoke with the maximum load of timber. Even should they not sleep the danger is clearly great.
Side Sectional Elevation (Pataling Type of Furnace).
Pataling Type of Furnace.