ABSTRACT of the ABBE BERTHOLON’s PAPER
on FIRES, and the MEANS of extinguishing them.
PUBLISHED IN THE LAUSANNE MEMOIRS.
This subject is important and interesting, although the Abbé has rather collected the observations and experiments made by others, than conveyed any new and original information. He ascribes the inflammability of bodies to the inflammable gas which they contain, and which, on their decomposition by heat, is let loose, and coming into contact with the atmosphere is ignited, and bursts out into flame. The principal part of the memoir is devoted to a detail of the means of preventing and extinguishing fires; and here the author’s chief advice, which is “in the construction of buildings, to employ as little as possible of those materials which yield inflammable air on their decomposition,” will be allowed to be perfectly just in theory, but will probably be little followed in practice: nor is the security resulting from brick floors likely to compensate, in this age of affected elegance, for their appearance. He informs us, however, that M. Ango, an architect of Paris, has contrived a method of constructing a floor with iron bars, instead of timber joists, which is even less expensive than the common mode. The wood used in buildings may be rendered uninflammable, by being steeped in a saline solution, and by being prepared with allum, even canvass and paper hangings may be made to burn without flame.
Many other precautions are mentioned by the Abbé, which we shall not detail, as they are universally known, and we believe pretty generally adopted. After describing the inventions of Mr. Hartly and Lord Mahon, together with a preparation similar to that of Lord Mahon’s recommended by M. Frederic, of Vienna, the Abbé gives an account of a substance, which he calls paper stone, invented by Dr. Faye, physician to the Swedish admiralty: its composition is not known, but from a chemical analysis it appears to consist of two parts of an earthly basis, and one of animal oil, mixed up with two parts of some vegetable substance. At Carlscrone a hut was built of dry wood, covered with this paper, which is not more than two lines in thickness, it was then filled with combustibles, which were set on fire and consumed without burning the building: the paper, which had been pasted on boards, was reduced to a cinder, and formed a kind of incrustation, which preserved them from the effects of the flame. As this paper readily takes any colour, it may be rendered ornamental as well as useful.
In his directions for extinguishing fires, the Abbé observes, that water, in which a small quantity of potash has been dissolved, is more efficacious than any other; he also recommends an engine called an hydraulic ventilator, invented by M. Castelli, which is worked by vanes instead of pistions, and may be managed by one person. The advantages ascribed by our author to this machine are very considerable, but we cannot suppress our astonishment on being told, that with a cylinder of only three inches in diameter, it will throw up more water than the largest fire engine; however, it certainly appears to be less expensive and more portable than the common forcing pumps, and may be of use in extinguishing a fire, before it has made any great progress. The utility of garden mould with wet sand in this respect, is well known, but it can seldom be applied, and we doubt the efficacy of the kind of catapult which the author recommends, for throwing it so any distance.
The remainder of the memoir contains some very just and obvious remarks on the necessity of a regular discipline among firemen, and it concludes with a description of the engines, cisterns and pipes at the opera house in Paris, the construction and arrangement of which the Abbé recommends to be adopted in every public theatre.