7 i8 THE POPULAR SCIENCE MONTHLY. 



cargo, packed in such a manner, and containing such elements, that 

 the barge was really a very efficient kind of torpedo. In her hold 

 there were about five tons of gunpowder and a quantity of benzoline 

 in kegs. This benzoline may be described as a very volatile species 

 of petroleum. At ordinary temperatures it gives off a highly-inflam- 

 mable vapor, and this, when mingled with the air in certain pro- 

 portions, becomes explosive the explosion running through it at the 

 rate of about two feet per second when it is confined in a tube. In 

 the case of the barge on the Regent's Canal, the cargo was closely 

 covered with a tarpaulin, to protect it from the weather. From the 

 moment, then, that this covering was put on by the bargemen, the 

 vapor given off by the benzoline began to accumulate in the hold, and 

 mingle with the air confined in the spaces between the various pack- 

 ages of the cargo. Thus the hold gradually became filled with a fiery 

 explosive atmosphere, and all that was wanted to produce an explosion 

 was contact with flame. In the little cabin, at the stem of the barge 

 a fire was burning, and there was an aperture in the bulkhead, or 

 partition, which divided the cabin from the hold. Through this the 

 benzoline vapor entered the cabin, and the air in it was soon as 

 vitiated as that under the tarpaulin in the hold. It was ignited by 

 the fire ; the explosion, beginning in the cabin, ran forward in a i'ew 

 seconds to the bow, and fired the gunpowder stowed there. 



Every one knows what followed. Half London was awakened by 

 the report, which was heard for miles around to the northward as 

 far as Finchley and Enfield, to the southward as far as Blackheath 

 and Woolwich. Within a radius of from half a mile to a mile from 

 the scene of the explosion houses were wrecked, windows blown in, 

 doors burst open, ceilings shaken down, ornaments and furniture 

 dashed to pieces. A massive bridge over the canal was destroyed, for 

 hundreds of yards its embankment was displaced, and the house 

 which stood nearest to it was so shaken that it had to be pulled down 

 next day. The effect was more like that of a severe shock of an 

 earthquake than any thing else. Fortunately no lives were lost ex- 

 cept those of the crew of the barge, but the destruction of valuable 

 property was enormous. 



Much alarm has been caused not only in London but throughout 

 the kingdom by this explosion in the heart of the metropolis, and it 

 will have a useful effect in calling attention to the dangerous character 

 of a material so largely employed as gunpowder, and the consequent 

 necessity of carefully regulating its manufacture, storage, and trans- 

 port, and seeing that these regulations are strictly enforced ; for, no 

 matter how perfect our precautions may be in theory, they are worse 

 than useless if we cannot secure their practical efficiency. Without 

 this, their only result must be to lull us into a false security. Gun- 

 powder, and its manufacture and transport, are now subjects in which 

 nearly every one is interested ; and we purpose to devote the following 



