“Musgrave’s Patent Warming and Ventilating Stove,” Fig. 41 (Musgrave & Co., Limited, 97 New Bond Street, London), is made upon the slow-combustion principle, to burn from 8 to 24 hours, but is much more highly finished than the last named, and is constructed in so many patterns and sizes as to be suitable for almost every purpose, from small dwellings to the largest buildings. The stove consists of an outer casing, within which is contained the fire-box and an air-chamber. The latter is provided with gills to increase the heating surface (see Gill stoves). The smoke and heat when leaving the top of the fire-box is carried down a flue-way to the bottom of the stove, and then up to the top again into the smoke-pipe; this flue-way is within the air-chamber, and so utilises the major portion of the heat passed into the flue; the fuel to be used is coke, which is the most suitable fuel for all slow-combustion stoves. For conservatories or where the air requires moistening these stoves are very neatly and effectually fitted with vaporising pans; and these stoves are also made to act as hot-air furnaces, and in combination with hot-water-pipe heating apparatus. Roberts’ patent terra-cotta stoves operate also by slow combustion and are self-acting, but possess the additional advantage of purifying and radiating the heat by the terra-cotta, which is contained between 2 concentric cylinders of sheet iron united at the base and top, the outer cylinder being perforated to allow of direct radiation of heat from the terra-cotta. The stove consists of 4 separate parts, namely, the stove body, its top or cover, the fire-box, which can be lifted in and out, and the stand, with draw and damper. The fire is lighted at the top and burns downwards, the air sustaining it being drawn upwards through the bottom of the fire-box and thence through the fuel. The stove can be placed in any position on an iron or stone base and connected with the nearest chimney flue by an iron pipe provided with soot-door elbows, care being taken to form a complete connection by abandoning any other open fire-grate in the room and screening it off by an iron or zinc plate. They emit no effluvium, as the terra-cotta gradually and completely absorbs all the caloric in its permeation through the shell before it is communicated to the outer air, which is thus warmed and diffused in a healthy condition over the room. The top of the stove is movable, so that the fire-box can be removed to be cleaned and recharged without moving the stove body, and a sand groove is inserted at the top where the cover rests, which is filled with fine dry sand to prevent any escape of smoke.