……………….Figure 1. Images are figs. 1 (left) and 9 (right) of Davy’s paper [11]. The left hand image represents the safe lantern with its airfeeder and chimney furnished with safety metallic canals. It contains about a quart of air. The sides are of horn or glass, made air tight by putty or cement. (A) is the lamp through which the circular air-feeding canals pass: they are 3 concentric hollow cylinders, distant from each other 1/26 of an inch: the smallest is 2 1/2 inches in circumference; their depth is 2 inches. (B) is the chimney containing 4 such canals, the smallest 2 inches in circumference: above it is a hollow cylinder, with a cap to prevent dust from passing into the chimney. (C) is the hole for admitting oil. (D) is a long canal containing a wire by which the wick is moved or trimmed. (E) is the tube forming a connection between the reservoir of oil and the chamber that supplies the wick with oil. (F) is the rim round the bottom of the lantern to enable it to bear motion. Davy’s fig. 9 (right) is a metallic gauze safe lamp. (A) shows the three screens of metallic gauze or flame sieves. (B) indicates wires for trimming the wick. Copyright The Royal Society.if the air were contaminated with fire-damp. Then came his crucial test. With the lamp described above, he tested it with the lantern supplied by air through two glass tubes one-tenth of an inch in diameter, the chimney being protected in a similar manner. He then introduced this lighted lantern into a large jar containing an explosive mixture of air and fire-damp: the flame simply increased in size and then was extinguished without causing the mixture in the jar to explode. It is instructive to quote what Davy wrote in his first paper [11, pp. 11?2] that he read to the Royal Society on 9 November 1815–just two weeks or so after addressing and solving the major problem that he agreed to investigate: It is evident, then, that to prevent explosions in coal mines, it is only necessary to use airtight lanterns, supplied with air from tubes or canals of small diameter, or from apertures covered with wire gauze placed below the flame, through which explosives cannot be communicated, and having a chimney at the upper part, on a similar system for carrying off the foul air; and common lanterns may be easily adapted to the purpose, by being made air-tight in the door and sides, by being furnished with the chimney, and the system of safety apertures below and above. Davy’s first paper [11], written, read and printed within but weeks of his being alerted to the dangers that coal miners were exposed when working at seams that emitted fire-damp, describes 11 distinct kinds of safety lamps. Two of them are reproduced in figure 1.rsta.royalsocietypublishing.org Phil. Trans. R. Soc. A 373:…………………………………………………Figure 2. The final form of the safety lamp. Fig. 11 in [11]. Copyright The Royal Society.Two short paragraphs from Davy’s first paper [11, pp. 11?2] also merit citation here: A candle will burn in a lantern or glass tube made safe with metallic gauze, as well as the open air; I conceive, however, that oil lamps, in which the wick will always stand at the same height, will be preferred. When the fire-damp is so mixed with the external order Lonafarnib atmosphere as to order Lumicitabine render it explosive, the light of the safe lantern or lamp will be extinguished, and warning will be given to the miners to withdraw from, and to ventilate that part of the mine. Davy’s secon………………..Figure 1. Images are figs. 1 (left) and 9 (right) of Davy’s paper [11]. The left hand image represents the safe lantern with its airfeeder and chimney furnished with safety metallic canals. It contains about a quart of air. The sides are of horn or glass, made air tight by putty or cement. (A) is the lamp through which the circular air-feeding canals pass: they are 3 concentric hollow cylinders, distant from each other 1/26 of an inch: the smallest is 2 1/2 inches in circumference; their depth is 2 inches. (B) is the chimney containing 4 such canals, the smallest 2 inches in circumference: above it is a hollow cylinder, with a cap to prevent dust from passing into the chimney. (C) is the hole for admitting oil. (D) is a long canal containing a wire by which the wick is moved or trimmed. (E) is the tube forming a connection between the reservoir of oil and the chamber that supplies the wick with oil. (F) is the rim round the bottom of the lantern to enable it to bear motion. Davy’s fig. 9 (right) is a metallic gauze safe lamp. (A) shows the three screens of metallic gauze or flame sieves. (B) indicates wires for trimming the wick. Copyright The Royal Society.if the air were contaminated with fire-damp. Then came his crucial test. With the lamp described above, he tested it with the lantern supplied by air through two glass tubes one-tenth of an inch in diameter, the chimney being protected in a similar manner. He then introduced this lighted lantern into a large jar containing an explosive mixture of air and fire-damp: the flame simply increased in size and then was extinguished without causing the mixture in the jar to explode. It is instructive to quote what Davy wrote in his first paper [11, pp. 11?2] that he read to the Royal Society on 9 November 1815–just two weeks or so after addressing and solving the major problem that he agreed to investigate: It is evident, then, that to prevent explosions in coal mines, it is only necessary to use airtight lanterns, supplied with air from tubes or canals of small diameter, or from apertures covered with wire gauze placed below the flame, through which explosives cannot be communicated, and having a chimney at the upper part, on a similar system for carrying off the foul air; and common lanterns may be easily adapted to the purpose, by being made air-tight in the door and sides, by being furnished with the chimney, and the system of safety apertures below and above. Davy’s first paper [11], written, read and printed within but weeks of his being alerted to the dangers that coal miners were exposed when working at seams that emitted fire-damp, describes 11 distinct kinds of safety lamps. Two of them are reproduced in figure 1.rsta.royalsocietypublishing.org Phil. Trans. R. Soc. A 373:…………………………………………………Figure 2. The final form of the safety lamp. Fig. 11 in [11]. Copyright The Royal Society.Two short paragraphs from Davy’s first paper [11, pp. 11?2] also merit citation here: A candle will burn in a lantern or glass tube made safe with metallic gauze, as well as the open air; I conceive, however, that oil lamps, in which the wick will always stand at the same height, will be preferred. When the fire-damp is so mixed with the external atmosphere as to render it explosive, the light of the safe lantern or lamp will be extinguished, and warning will be given to the miners to withdraw from, and to ventilate that part of the mine. Davy’s secon.
