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NA TURE 



{March 19, 1885 



of the War Department. Although it may he hoped that their 

 continuation will lead to further data and conclusions of practical 

 and public importance, it is thought that some account of facts 

 already elicited may interest the members of the Royal Institution, 

 and possess some general value. 



Ever Mnce liquids which, more or less rapidly, involve in- 

 flammable vapour when freely exposed to air, or partially con- 

 fined, have been in extensive use, casualties have occurred from 

 time to time through the accidental or thoughtless ignition of the 

 mixtures of vapour and air thus formed, whereby more or less 

 violent and destructive explosions have been produced, often 

 followed by the ignition of the exposed liquid which is the source 

 of the explosive mixture, and by the consequent frequent deve- 

 lopment of disastrous conflagrations. 



Many instances are on record of explosions, sufficiently 

 violent to produce effects destructive or injurious to life and 

 property, resulting from the application of flame to vessels 

 which had contained either the more volatile coal-tar- or 

 petroleum-products, or strong spirituous liquids, apd which, 

 though they had been entirely or nearly emptied of their con- 

 tents, still contained, or retained by absorption within their body, 

 some of the volatile liquid, this having, by evaporation into the 

 air in the emptied receptacle, produced with it a more or less 

 violently explosive mixture. Thus, a loud explosion occurred at 

 the entrance of a lamp-maker's shop in Whitecross Street, 

 which was found to have been caused by a boy throwing a piece 

 of lighted paper into a cask standing under the gateway, which 

 had contained benzoline ; two boys were very seriously injured 

 by the blast of flame which was projected from the barrel. A 

 perfectly analogous accident was soon afterwards reported in the 

 papers as having occurred at Sheffield, with serious injury to the 

 author of the catastrophe and another boy : and a very similar 

 case occurred at Exeter during the removal of some empty 

 benzoline barrels, consequent upon a boy applying a lighted 

 match to the hole of one of them. Again, at Spaxton in 

 Somersetshire, a young man applied a light to the hole of a 

 benzoline cask, described as nearly empty, which was landing 

 in the road, when three young men were blown across the road, 

 one of them being so seriously injured about the head that he 

 died. 



Explosions with similarly disastrous results have also been 

 publicly recorded as having resulted from the application of a 

 light to rum puncheons and whisky casks, even some time after 

 they have been emptied of their contents, the evaporation of the 

 alcohol absorbed by the wood having sufficed to convert the 

 confined air into a violent explosive mixture. 



The readine-s or extent to which inflammable vapour is 

 evolved from those products of the distillation of petroleum, or 

 of shale or coal, which are used for illuminating purposes, 

 differs of course considerably with the character of these liquids. 

 Those which are classed as petroleum spirit (known as gasoline, 

 benzine, benzoline, naphtha, japanners' spirit, &c. ), and in re- 

 gard to which there exist very special precautionary enactments, 

 are, it need scarcely be said, of far more dangerous character 

 than those classed as burning oils, which include the paraffin oils 

 obtained from shale and the so-called flashing points of which 

 range from 73° to above 140° Fahrenheit. The rapidity with 

 which the vapours, evolved by the more volatile products on 

 exposure to air, or by their leakage from casks or barrels, diffuse 

 themselves through the air, producing with it more or less violent 

 explosive mixtures, has been a fruitful source of disaster, some- 

 times of great magnitude. The lecturer had occasion to refer, 

 in his discourse of 1875, to an accident at the Royal College of 

 Chemistry of which he was a witness, in 1847, when the lamented 

 Mr. C. B. Mansfield was engaged in the conversion of a quantity 

 of benzol into nitrobenz >1 in a capacious glass vessel, which 

 suddenly cracked, allowing the warm liquid hydrocarbon to 

 escape and flow over a large surface. This occurred in an apart- 

 ment 38 feet long, about 30 feet wide, and 10 feet high ; there 

 was a gas jet burning at the extremity of the room opposite to 

 that where the heated liquid was spilled, and within a very brief 

 space of time after the vessel broke, a sheet of flame Hashed 

 from the gas jet along the upper part of the room, to the spot 

 where the fluid lay scattered. 



The origin of a fire which occurred at some mineral oil stores 

 at Exeter in 1882 affords another striking illustration of the 

 great rapidity with which the vapour of petroleum spirit will 

 diffuse itself through the air. The store which caught fire, and 

 which contained both petroleum oil and spirit, or benzoline, was 

 one of a range of arched caves upon the bank of a canal, being 



separated from it by a roadway about 50 feet wide. It was a 

 standing rule at the stores that no light should be taken to any 

 one containing benzoline. The casks which contained this 

 liquid were to be removed, and the foreman, desirous of be- 

 ginning this work early, and forgetful of the rule, went to the 

 store shortly before daylight, carrying a lighted lantern, which 

 he placed upon the ground at a distance of several feet from the 

 door. He then proceeded to open these. As he did so, he 

 noticed a very powerful odour of benzoline, and, almost imme- 

 diately, he saw a flash of flame proceed from the lantern to the 

 store. He had just turned to escape, when an explosion occurred 

 which blew the doors and the lantern across the canal ; the benzo- 

 line in the store was at once inflamed, and flowed out into the 

 road and upon the surface of the water, firing a small vessel 

 which lay against the quay, and setting fire to the stores of 

 benzoline contained in two neighbouring caves. 



Many exemplifications might be cited of the danger arising 

 from the accidental spilling or escape of petroleum spirit (or 

 even of oils of very low flashing point) in the ordinary course of 

 dealing with these liquids, as in stores where there is but very 

 imperfect ventilation, and in some part of which a flame exists, 

 or is carelessly introduced ; or from the escape of spirit or its 

 vapour from stores or receptacles to adjacent spaces where, its 

 existence being unsuspected, the ignition of the resulting 

 explosive mixture of vapour and air may be at any time brought 

 about. 



Without referring to accidents which have been due to flagrant 

 carelessness in introducing a flame or striking a light in a store 

 where petroleum vapour is likely to exist in the air, or where 

 some form of spirit has been accidentally spilled, a few instances 

 may be quoted which illustrate the magnitude of casualties liable 

 to arise from the causes just referred to. Some years ago an 

 explosion productive of much damage occurred in a sewer at 

 Greenwich, and was clearly traced to the entrance into the sewer 

 of some petroleum products (from a neighbouring patent gas 

 factory) ; the vapours from these had diffused themselves through 

 the air in the sewer to a considerable distance, forming with it 

 an explosive mixture which must have been accidentally ignited 

 at one of the sewer openings in the street above. Last spring a 

 similar accident o:curred at Newport in Monmouthshire, a 

 quantity of benzoline having escaped into a sewer from a neigh- 

 bouring store ; the ignition of the resulting explosive mixture of 

 vapour and air, with which a considerable length of the sewer 

 became filled, tore up the roadway to some distance, several 

 persons being thrown down. A terrific disaster of the same 

 class was reported from San Francisco in November, 1S79. 

 During the driving of a tunnel in the San Jose Santa Cruz Rail- 

 way, a vein of petroleum became exposed by the excavators, 

 who were, of course, working with naked lights. Three violent 

 explosions occurred in consequence, in rapid succession, result- 

 ing in the death of twenty-five Chinamen and in the injury of 

 seventeen others and two white men. 



Another accident, which occurred near Coventry nearly five 

 years ago, may be quoted in illustration of the unsuspected 

 manner in which explosive gas-mixtures may exist in localities 

 which, to the superficial observer, may appear to have no con- 

 nection with a neighbouring locality where volatile liquids are 

 liable to escape confinement. 



A dealer in benzoline spirit kept his small store of that liquid 

 (from 20 to 80 gallons) in an apartment of his house, upon the 

 basement, the floor of the room being paved with red bricks. 

 At a distance of about three feet from the store-room there was 

 a well, the depth of which to the surface of the water was twenty 

 feet. The well was closed in almost entirely with planks covered 

 with earth. The water in the well being found foul, the owner 

 had the latter uncovered, with a view to its being cleared out. 

 The workman in charge of the operation, after having been 

 engaged for three hours in pumping out a large quantity of the 

 water, lowered a lighted candle into the well, according to the 

 usual practice, to see whether he could de-cend with safety, 

 when, while bending over the opening, he perceived a blue 

 flame shooting upwards, and was violently thrown back and 

 badly burnt, a woman who was watching him being similarly 

 injured. The benzoline which had been spilled from time to 

 time in small quantities in filling the cans of customers had 

 readily passed through the porous brick upon which it fell, and, 

 gradually permeating the soil beneath, had, in course of time, 

 drained into the adjacent well. That this must occur under the 

 circumstances described would have been self-evident to anyone 

 acquainted with the behaviour of these liquids and with th 



