AIINOTT'S STOVE. Dr. Arnott has dis tinguished himself by many ingenious con trivances, brought forward by him—not for the sake of profit, but as conducive to general health and comfort. The Water-bed, the Stove, the Ventilator—all are familiarly known by the name of..the benevolent physician who invented them.
Arnott's Stove is one of the many varieties of close stove, in which the cheerfulness of an open English fire is abandoned for the sake of a more efficient mode of burning the fuel. It was in 1838 that Arnott published his work on Warming and Ventilation, in which he so beautifully and simply explains the philo sophy of the fire-place. He shows how, in a common open fire we waste a large amount of fuel, heat our rooms very unequally at different distances from the fire-place, cause cold draughts to flow in from the doors and win dows, and a stratum of cold air to lie next the floor and near the feet, leave the rooms with out good ventilation, occasion much unneces sary smoke and dust, waste much time in attending to the fire, entail danger to person and to property, and necessitate frequent cleaning of chimneys. It was to remove some of those evils, and to lessen others, that he suggested his new form of stove—the guiding principle of which is, to allow the fuel to burn very slowly, through the controlling agency of a valve for admitting the air. The stove usually consists of an exterior iron case, square or cylindrical, lined with fire clay ; the fuel is burned in a box or vessel within the case ; there is one opening in the outer case to admit fuel, another to remove ashes, and a third at which a flue may be fixed to carry off the products of combustion. All these aper
tures being closed, air must enter to feed the fire in some other way. This is admitted by a very small aperture near the level of the burning fuel ; and the aperture is closed by a valve which forms the distinguish ing feature of the Arnott stoves. Many vari eties of the valve hare been adopted ; but all of them are self-acting. When the fire is too fierce, the valve closes automatically, and re fuses to admit any more air until the heat becomes subdued ; but under average circum stances the valve remains open, and a small but steady stream of air enters the stove. The most successful contrivance is found to be a tube containing mercury, placed within the outer case, and bending round to the exterior in the form of an inverted siphon ; when the mercury becomes heated, it expands, rises in the tube, and thus moves a small piece of apparatus which governs the valve.
The relation which Arnott's stove bears to stoves and heating apparatus generally, is noticed under WADAIING AND VENTILATING.