1 823 .] Gas Light Establishments. 4 1 7 



equal to 31 barrels. Fifteen such gasometers, therefore (the 

 number in Peter-street), would, with this mixture, produce a 

 force equal to that of 465 barrels of gunpowder. 



A second experiment was subsequently made with a greater 

 proportion of the carburetted hydrogen. 



Second experiment. 

 346 cubic inches of carbu-"] 



i e ? e o h y dro § en ; and I Average of threes 

 1,382 cubic inches of' roun 3 s with the I 



common air, being one- f game bd] J 



fifth to four-fifths were ■' 



fired, J 



16 drachms of gunpowder^ 



were found to produce > Ditto, ditto. 



nearly the same effects. J 



Feet. 



158 



113 



Recoil of cylin- 

 der. 



76° 



74 



One cubic foot, therefore, of gas, mixed in this proportion, 

 would give an explosive force equal to five ounces of gunpow- 

 der, or 288 cubic feet equal to one barrel ; one gasometer, there- 

 fore, of 15,000 cubic feet so mixed, would be equal to 52 bar- 

 rels and a quarter, and 15 such gasometers to 783 barrels and 

 three-quarters of gunpowder. 



For the mere purpose of determining the risk of large accumu- 

 lations of carburetted hydrogen gas, it was evidently unneces- 

 sary to try any further experiments, since it was thus proved, 

 that if by any accident the contents of one of the gasometers in 

 Peter-street were to be supposed to have escaped into the gaso- 

 meter-house, so as to form a mixture with the surrounding 

 atmosphere, in the proportion of one-fifth of gas, an explosive 

 mixture would be created equal to upwards of 50 barrels of gun- 

 powder ; and that if the contents of the whole of the gasometers 

 at this station could be supposed to have escaped in like man- 

 ner, an explosive force equal at least to 700 barrels might be 

 created ; and that on the same principle, the entire leakage of 

 one of the large gasometers of 39,000 cubic feet in Dorset-street, 

 might produce an explosive mixture equal to about 135 barrels 

 of gunpowder. 



It is true, that in the ordinary condition of the carburetted 

 hydrogen contained in the gasometers, it is not explosive ; it 

 wants the admixture with common atmospheric air to make it 

 so ; but then it must not be forgotten, that this requisite ingre- 

 dient is the circumambient atmospheric air, that surrounds the 

 gasometers, and is in constant contact with every part of them, 

 so that the union of the two ingredients in certain dangerous 

 proportions may always be effected, either internally or exter- 

 nally, by unforeseen accidents ; as the destruction of a gasome- 

 ter by lightning, producing both the mixture and the ignition at 

 the same moment ; the same by the burning of the gasometer- 

 New Series, vol. v. 2 e 



