[18] This apparatus will heat the air in a room to 84° in the coldest weather, and is particularly calculated for cotton mills, and other purposes. His invention is considered to be a judicious application of a well known principle. Count Rumford heated rooms in a similar manner by steam, which may be seen in the Repository of Arts vol. xv, p. 186. A Mr. Green of Wandsworth, England, obtained a patent in 1793, for warming rooms, by heated air, heated with steam. Steam pipes, however, are now in use in the United States. In consequence of the great quantity of latent caloric in steam (about 1000 degrees) which is given out as free heat in its condensation, this principle has been judiciously applied not only to the warming of apartments, but to the boiling of dye kettles, and other purposes. See an account of Woolf's steam apparatus, subsequent pages.
[19] The principal workmen they describe, are a master powderer, a master carpenter, a master cooper, a head boy, (Garçon) employed in the pulverization of the substances, another for the fabrication of charcoal, one for every mill, besides workmen for aiding in the charring, for the mill, &c.
[20] Traité sur l'art de fabriquer la poudre à canon, par MM. Bottée et Riffault may be consulted.
[21] This is a mixed gas, composed of carburetted hydrogen, and carbonic oxide.
[22] His son wrote a work, having the following title: "Thoughts concerning that last and most perfect work of nature, and chief of metals, gold, its wonderful properties, generation, affection, effects, and fitness for the operations of art; illustrated by experiments," from the Latin. Hamburgh, 1685, 8vo.
[23] In the year 1777, Lord Mahon, afterwards Earl Stanhope, exhibited some experiments, to prove the certain, cheap, and simple method of securing houses against fire, without making use of either brick, stones, tiles, iron, or any such incombustible material. A building, entirely constructed of wood, and of lath and plaster, with a very small quantity of sand laid under the floors, which were of deal, was attempted to be set on fire by means of a large quantity of dry burning fuel, faggots, straw, pitch and other combustibles, with which the lower room of this building was filled, from the floor to the ceiling almost in every part. The whole mass of fire burnt out without doing the least damage. Those who were in the next story, directly over the conflagration, did not perceive the least degree of heat. A wooden stair case, made in the same manner, also resisted the flames.
[24] The imitation of thunder, rain, hail, &c. for theatrical purposes, is variously performed. Mr. Nicholson, in describing an exhibition he saw in London, (See [Phantasmagoria],) remarks, that thunder was imitated very accurately, by means of sheet iron plates. The noise of rain and hail may be imitated by procuring a thin hollow cylinder of wood, about ten inches wide, and two or three feet long; dividing its inside into five equal parts, by boards, placed obliquely, of five or six inches, observing to let there be between them and the wooden circle, a space of about one-sixth of an inch, and then introducing about four or five pounds of shot, and turning it upside down. The shot will pass through the various partitions, and resemble the fall of rain. If large shot be used, the noise will be increased, and resemble hail.
According to the Dictionnaire de l'Industrie, (article Tonnerre artificiel), thunder is imitated, by making a hexangular case of sheet iron, and putting stones or small balls into it, and rolling it more or less swiftly. Another mode is to roll cannon balls on a floor, on which is loosely nailed, at certain distances apart, strips of wood or lath. A clap of thunder is imitated by letting fall on each other, very suddenly, a number of sheet iron plates, having them previously suspended, or strung on a cord, which must be vertical. In 1784, M. Michael, (Journal de Paris) made a machine, which imitated thunder, so completely, as either to produce the most violent clap, or the most distant rumbling, with intermediate variations. Parchment, stretched over a frame, has likewise, been used for the same purpose. The distant thunder may be represented in this manner; but, to produce a sharp noise, or clap, something more is required.
[25] Whoever walked the streets of Rome, at night, without a lantern, was under the necessity of creeping home in perfect darkness, and in great danger, like Alexis, in Athenæus. Antioch, Rome, and a few other cities had public lanterns in streets which were most frequented. Libanus, who lived in the beginning of the fourth century, in praising his native city, Antioch, says, that "the light of the sun is succeeded by other lights, which are far superior to the lamps lighted by the Egyptians on the festival of Minerva of Sais. The night differs from the day only in the appearance of the light. With regard to labour and employment, every thing goes on well. Some work continually; but others laugh and amuse themselves with singing." In another passage, in the oration to Ellibichus, the same author tells us, that the ropes from which the lamps that ornamented the city were suspended, had been cut by some riotous soldiers, not far from a bath. "Proceeding," says he "to a bath, not far off, they cut, with their swords, the ropes, from which were suspended the lamps that afforded light in the night-time, to show that the ornaments of the city ought to give way to them." Jerome also makes it appear, that Antioch was lighted with lamps; for, he remarks, that, in an altercation between a Luciferan and an Orthodox, an adherent to the schismatic Lucifer disputed in the street with a true believer, till the streets were lighted, when the listening crowd departed, and that they spat in each other's face, and retired. Edessa, in Syria, was lighted in the fifth century, and the governor of that city ordered, that a part of the oil, which was before given to the churches and monasteries, should be burnt in the streets. While illuminations were considered emblematical of public rejoicing, the reverse was considered a token of public sorrow; to denote which, on occasions of great misfortune, it was customary not to light the streets. Valerius quotes a passage of Libanius in proof of this assertion, where it is said, that the people of Antioch, in order to mitigate the anger of the emperor, bethought themselves of lighting either no lamps, or a very small number. In 1588, Paris was lighted up with falots, or vases filled with pitch, rosin, and other combustibles. The Abbé Laudati let out torches and lanterns in Paris, in 1662.
[26] In the Archives des Découvertes, &c. several new lamps are described, as follows: A lamp, invented by count Rumford noticed by him in a memoir on the light of lamps, and the means of increasing it; a new lamp with a double current of air, by Lenormand; star lamp by Bordier; reverberatory lamp for towns, &c. by de Thirville and Bordier; a modified thermo-lamp by Winsor; a new lamp by Baswell; the economical lamp of inflammable gas, by Murdoc, and economical lamp by Lambertin; the cupola lamp by Vivien; new lamp with a porcelain reflector by L'Ange; the hydrodynamic and chemical lamp, by L'Ange; the portable lamp by count Rumford; horizontal reflectors, with parabolic surfaces in revolving, and parabolic reflectors, simple and double, by Argand and Bordier Marcet; improved lamp, by Marcet; thermo-lamp by Sobolewsky and Horrer; watch lamp by Dumouceau; various lamps, with carburetted hydrogen; the polyflame lamp, of Rumford; the curved lamp by Connain; the enamellers' lamp, and hydropneumatic lamp by Tilley, &c. Davy's safety lamp is described in Brande's Chemistry, and in Ure's Chemical Dictionary. See [Aphlogistic lamp.]