CALORIC

The chemical name of the power or matter of heat. CALORIFÈRE OF WATER. ( Calorifère d’eau , Fr.; Wa er-Heitzung , Germ.) In the Dictionnaire Techno log i que , vol. iv., published in 1823, we find the following description of this apparatus, of late years so much employed in Great Britain for heating conservatories, . by hot water circulating in pipes :— IMG:4147767755307473660_illo0244.png:Water heater “This mode of heating is analogous to that by stove pipes: it is effected by the circulation of water, which, like air, is a bad conductor, but may serve as a carrier of caloric by its mobility. We may readily form an idea of the apparatus which has been employed for this purpose. We adapt to the upper part of either a close kettle, or of an ordinary cylindric boiler A , fig. 252 , a tube B , which rises to a certain height, then descends, making several sinuosities with a gentle slope till it reaches the level of the bottom of the boiler, to whose lowest part, as that which is least heated, it is fitted at C . At the highest point of the tube F we adapt a vertical pipe, destined to serve as an outlet to the steam which may be formed if the temperature be too much raised: it serves also for the escape of the air expelled from the water by the heat; and it permits the boiler to be replenished from time to time as the water is di ipated by evaporation; lastly, it is a tube of safety. “The apparatus being thus arranged, and all the tubes as well as the boiler filled with water, if we kindle fire in the grate D , the first portions of water heated, having become specifically lighter, will tend to rise: they will actually mount into the upper part of the boiler, and, of course, enter the tube B F : at the same time an equivalent quantity of water will re-enter the boiler by the other extremity C of the tube. We perceive that these simultaneous movements will determine a circulation in the whole ma of the liquid, which will continue as long as heat is generated in the fire-place; and if we suppose that the tubes, throughout their different windings, are applied against the walls of a chamber, or a stove-room, the air will get warmed by contact with the hot surfaces; and we may accelerate the warming by multiplying these contacts in the mode indicated. “This calorifère cannot be employed so usefully as those with heated air, when it is wished to heat large apartments. In fact, the pa age of heat through metallic plates is in the ratio of the difference of temperature and quantity of the heating surfaces. In the present case, the temperature of the water, without pre ure, in the tubes, must be always under 100° C. (212° F.), even in those points where it is most heated, and le still in all the other points, while the temperature of the flues in air stoves , heated directly by the products of combustion, may be greatly higher. In these stoves, also, the pipes may without inconvenience have a large diameter, and present, consequently, a large heating surface; whereas, with the water calorifère , the pre ure exercised by the liquid upon the sides of the tubes being in the ratio of the surfaces, we are obliged, in order to avoid too great pre ure, to employ a multitude of small tubes, which is expensive. Lastly, if the hot-water circulation is to be carried high, as may be often nece ary in lofty buildings, the pre ure resulting from the great elevation would call for proportional thickne in the tubes and the boiler: for these reasons, and others which we shall state in treating of heating by steam, it appears that water cannot be advantageously substituted for air or steam in the applications above stated; yet this mode of heating presents very decided advantages where it is useful to raise the temperature a small number of degrees in a uniform manner.” See Incubation, artificial . “M. Bonne main applied, with much succe , these ingenious proce es of heating by the circulation of water, to maintain a very equal temperature in hot-houses ( serres-chaudes ), in stoves adapted to artificial incubation, and in preserving or quickening vegetation within hot-houses, or outside of their walls, during seasons unpropitious to horticulture. “Since the capacity of water for heat is very great, if the ma of it in a circulation-apparatus be very considerable, and the circulation be accelerated by proper arrangements, as by cooling the descending tube exterior to the stove-room, we may easily obtain by such means a moderately high and uniform temperature, provided the heat generated in the fire-place be tolerably regular. We may easily secure this e ential point by the aid of the fire-regulator , an instrument invented by M. Bonne main, and which is described under the article Incubation , because there its use seems to be indispensable.” From the above quotation, and, more especially, from the evidence adduced in the article Incubation , we see how little claim the Marquis de Chabannes, or any of his followers, can have to invention in their arrangements for heating apartments by the calorific motions of the particles of water, enclosed in pipes of any kind.