Coal Oil and Kerosene Lamps.—About 1845 was introduced in the United States a compound that was known as burning fluid, or, from its inventor's name, Potter's fluid. This was a highly explosive illuminating fluid, com posed of a mixture of about three parts of wood alcohol to one of purified oil of turpen tine. This was burned in lamps provided with long, slender, tapering brass tubes, secured to a disc that screwed into a collar fitted to the upper part of the lamp. The wick was round, firmly woven cotton, which closely fitted the wick tubes. This was to prevent the escape of the vapor from the fluid. Little thimble-shaped oaps, secured by small chains, were provided to cover the end of the wick tubes when the lamp was not in use. This was to prevent the evaporation of the highly volatile burning fluid. Camphene was the trade name of a burning fluid composed of oil of turpentine, purified by being distilled over quick-lime. This fluid was burned in lamps provided with the same class Of burners as that described for burning fluid. The highly explosive nature of these dangerous compounds rendered them unpopular for do mestic use, and they were soon displaced by the safer and cheaper kerosene oil, which came into general use about 1860. This was first called coal-oil, and in some localities mineral oil, while in others it was known as petroleum oil. Many hundreds of lamps and burners have been in vented to use this cheap illuminant. In all suc cessful kerosene burners a glass chimney is necessary. Many attempts have been made to produce a kerosene burner that would afford a clear, brilliant, steady, smokeless flame, without a chimney, but so far no good, practical lamp has been put on the market that successfully accomplishes this much-desired result. A lamp was made and introduced in 1869 that burned a vapor of naphtha without a chimney. While the flame from this device was white and bril liant, the light was flickering, and when moved about emitted annoying smoke. The highly ex plosive nature of the fluid burned made its common use unsafe, so that the vapor lamp never became popular. What is known as the German student lamp, supplied with an im proved Argand burner, and the so-called Rochester lamp, employing another modifica tion of the Argand burner, are the best and most successful kerosene lamps so far intro duced. There are hundreds, if not thousands, of different kerosene oil burners attached to an almost endless variety of lamps now on the market. These embrace hand lamps, table lamps, piano lamps and a variety of library and parlor lamps that are .remarkably rich in orna mentation and graceful in form and shape, but in the construction designed to assist the com bustion of the oil in producing the illumination the same general principles are involved, and with the exception of the smaller hand lamps the original Argand burner principle is adhered to, with slight modifications and improvements. In the small hand lamps a perforated hood shaped cap surrounds the wick making a dome like chamber through which the air drawn from the outside is deflected into the flame, thus sup plying the needed oxygen. The flat ribbon wick is used in most of the smaller lamps, the wick being moved up and down by a spur-wheel as before described.
Safety Lamps are lamps so constructed that the danger from the foul explosive air of mines, especially deep coal mines, may be les sened or prevented, by so protecting the flame of the miner's lamp that it will not come in direct contact with the mixed carburetted hydro gen and atmospheric air, which is often present in such quantities as to create an element of great danger. The first safety lamps were called
"Steel Mills,> and were devices in which small steel wheels, with roughened edges, were rapidly revolved against a flint, securely held by a pow erful spring. The sparks thus produced af forded an intermittent light which was sufficient to illuminate the more dangerous parts of the deep mines. But as this lamp necessitated the employment of a boy to revolve the wheel white the miner was engaged in his work, it proved too expensive for economic use. In 1813 Dr. Canny in England introduced the first true safety miner's lamp. In his invention he pro duced a lamp in which the external air was ad mitted to the burner through a chamber con taining water, while the flame was protected by a glass bulb, the product of combustion escaped through perforations in a flat support on which the glass bulb rested. This con trivance was so cumbersome, and so liable to breakage, that it never came into general use. In 1815 George Stephenson and Sir Humphry Davy contrived a safety lamp that, with slight modifications, has continued in use up to the present time. The air to support combustion was admitted to the flame through small open ings in the bottom of the lamp, while the flame was protected by a glass, upright cylinder, the top of which was covered with a wire gauze cap. Several forms introducing slight changes from the original Davy lamp have been made. The lamp in which the flame is protected by a wire gauze cylinder in the place of a glass one was a later invention of Sir Humphry Davy. Mackworth's safety lamp was an improvement over the Canny lamp, and introduced features common to that and the Davy lamp. A water chamber was provided through which the ex ternal air passed before reaching the flame. Immediately surrounding the flame was a thick, glass cylinder and above that a fine wire gauze cylinder, making a continuous protection about the flame. Outside of this was an additional wire gauze cylinder added as a means of pro tection against breakage. Lamps for jewelers, chemists and laboratory use are in reality minia ture furnaces, and are generally provided with wide wick supports in which are large cotton wicks. Alcohol is the most common fluid used for generating heat in these lamps. Painter's lamps are contrivances in which naphtha is burned under pressure, the resulting heat being employed in the removing of old paint from surfaces which it is desired to repaint. Hand lanterns are simply lamps of various forms, surrounded by glass globes or cylinders to protect the flame from the wind. Ancient Ian terns were provided with transparent protectors made of horn scraped thin to permit the light to be reflected through. The word lantern is a combination of lant-horn, and was employed to express a light which was protected with a transparent horn. Another form of early lantern, now designated by collectors as the Fawkes lantern," was of tin, perforated with small punctures through which the light shone. Early hall, or as they were called entry, lanterns were often massive andelegant ground glass globes, ornate and beautiful to a marked degree. Either candles or oil were used as illuminant. They were suspended by chains from the ceiling and a glass smoke pro tector was provided in those of more elaborate make. (See ELECTRIC LIGHTING; GAS 'LUMINA noN). Consult Bolton, H. C., of Sepulchral and Perpetual Lamps' (London 1879) ; Hough, W., (Lamps of the Esquimo' (Washington 1896); Norton, C. A. Q., and Lamps of Early New England,' (in Con necticut Magazine Hartford 1903-04) ; Walters, H. B., and Roman Lamps in the British Museum> (London 1914).