EXPLOSION OF KEROSENE LAMPS.

Clutha Leader, Volume IV, Issue 204, 7 June 1878, Page 7

EXPLOSION OF KEROSENE LAMPS.

1 A correspondent^ to the Scientific American writes as follows : — " A few evenings ag'o, a lamp burning- in my kitchen suddenly went to pieces ; the oil blazed up and ran off the table in a burning stream, setting; fire to the floor; The oil blazed up two or three feet high, and but for prom pi attention the results would have been serious. The lamp was of glsiss, of the flat form, said to be the best ; the oil vessel would hold half or three-quarter? of a pint ; the wick was long* enough to reach the bottom. The flame was turned rather low, but by no means as low as possible, and tho lamp had been burning* the greater part of two evenings since it had been filled, so that it could not have been too full. It was not exposed to a draft and could not have been upset or shaken ; no one had been in the room for at least half an hour previously. The oil was claimed to be able to stand 150deg. fire test ; and immediately after the accident some of the oil was tried with a lighted match, but it would not burn. The explosion did not throw any pieces of the lamp more than a few inches, and the oil was not scattered at all ; the noise was so slight that, when heard in an adjoining room, it was supposed that the chimney had broken and fallen off. Question 1. Why did the oil that ran from the lamp burn as freely as turpentine, while the oil poured from the can would not burn at'alH 2. Is any kind of oil safe, aDd (3) if so, how can the consumer test it ?" As this subject involves the protection ol life and property, and as similar instances have lately become common, we think it of primary importance that the causes of such accidents should be well known, and that some prevailing errors should be corrected, as they lead to precisely such catastrophes as the one in question. But our correspondent was more fortunate than one acquaintance of ours, who, coming home late in the evening, found his house entirely burnt down, the only possible cause being 1 that a servant had left a kerosene lamp, partially burnt out, alight in her room, and as the flame burned down an explosion doubtless followed, spread the oil, and set the house in flames. Our correspondent's accident illustrates the following popular errors : 1. He stater, that the lamp was of the flat kind, said to be the best. Some of the flat lamps have the flame so near to the body of the lamp that the containing vessel and the oil become warm ; then the latter easily reaches the temperature of the flashing point, 110, 120, or more degrees. This shows that flat lamps are not by any means the safest. 2. He also says : " The lamp had been burning the greater part of two evenings since it had been filled, and so could not have been too full." A full lamp cannot explode ; explosion is caused by the space in the lamp over the oil, which, when filled with air mixed with vapor of the oil, forms an explosive mixture. A barrel full of petroleum can take fire, but will never explode. Not long ago, we had an illustration in New York of the dangers of empty petroleum barrels : A man struck a match, in order to light a pipe, upon an old petroleum barrel, and it exploded at once, nearly killing him. The barrel was filled with a mixture of petroleum vapor and atmospheric air, which happened to be in the proportion necessary to make an explosive mixture, namely, 1 volume of vapor to about 10 volumes of air. In fact, the addition . of 10 per cent, of petroleum vapor to ' common air makes a most dangerous mixture. It is, therefore, an error to suppose that a lamp can be too full ; and we advise housekeepers to fill them, and never let them burn out, and to avoid as much as possible any empty space over the oil. 3. It is a popular mistake to test the oil at the common temperature. Only benzine and naphtha will take fire under these circumstances 5 but if the kerosene is adulterated with the latter, the mixture may be ignited also. Good kerosene, when cold, will burn only with a wick ; but if we warm it. the vapor will first flash on nearing a flame; if w© warm it more, the oil itself will take fire. We should, therefore, warm the oil when we wish to test it ; the simplest way is to pour some in a tablespoon and keep it; in contact with the surface of hot water, of which the temperature can be found with a common thermometer ; if the oil is claimed to stand the fire test of 150deg., it ought not to burn before being heated to that degree. It will thus be seen that our correspondent's lamp exploded because it had burned for a long time since tilled, leaving a space over the oil, which filled with its vapor as the lamp, being of the flat kind, became warm. When the flame was turned down, the lamp cooled a little, the vapor contracted, and its contraction drew in air, until enough of it had entered the space above the oil to form the explosive mixture above referred to. This mixture was set on fire by tho flame, and, of course, the lamp was broken by the explosion. The kerosene left in the flat lamp became heated by the flame, being much peare.r to it than it would have been in a lamp of a taller or more nearly globular form, and of course was therefore ready to burn, while the cool kerosene in the can was not. The

pieces ot glass were not scattered mucli J * and the explosion made little noise, because either there was not a very large space filled with the' explosive mixture, or the explosion took place as soon as the mixture became inflam» maWe, and before enough air had been drown in to give the mixture the most effective proportion. We believe that these remarks solve the 'difficulties which many readers have encountered ; and we will close this nr:icle with a few words of advice. 1. Do not buy lamps in which the flame is too near the body of the lamp, Kerosene can ascend in a long wick j and short wiclcs only tend to heat lamps and oil, and to encourage accidents. 2. Use, tho cylindrical wicks, with the draught in the middle; and use a long 1 burner, which brings the flame to a distance of at least three inches from the body of the lamp. The form of the brass student's lamp is a. very safe, one, as in this the oil reservoir is at a long distance from the flame. 3. Be always prepared to test the oil you buy, as already described. You can heat the water to boiling point, and then mix it with cold water until it shows -160°, or any other desired temperature, If people would take the trouble to apply this simple test occasionally, they would largely diminish the number of accidents. v 4. Keep the lamp full of oil, and never let the kerosene burn away I much, and so avoid the dangerous empty space above the oil, especially when the lamp is flat and the flame not far above it. 5. Never turn a kerosene lamp low j rather extinguish •_ it, as, besides tho possible danger already described, there is the nuisance of an i unpleasant and unwholesome smell given off when the wick is turned lower than it is intended to be used. The cause of. this is imperfect combustion, and the consequent evolution of injurious gases.