That the coal-gas, when mixed with a certain portion of common air, in close vessels, may be inflamed by the contact of a lighted body, as has been stated, page 98, is a fact sufficiently known. But the means of preventing such an occurrence in the common application of gas-lights, are so simple, easy, and effectual, that it would be ridiculous to dread danger where there is nothing to be apprehended. In speaking thus of the safety of the gas-light illumination, I do not mean to deny that no possible circumstances may occur where the coal-gas may be the cause of accident. It is certain that the gas, when suffered to accumulate in large quantities in close and confined places, where there is no current of air, such as in cellars, vaults, &c. and where it can mix with common air, and remain undisturbed, that it may be liable to take fire when approached by a lighted body; but I do not see how it is probable that such an accumulation of gas should take place in the apartments of dwelling houses. The constant current of air which passes continually through the rooms, is sufficient to prevent the possibility of such an accumulation ever to take place. And with regard to the bursting of the pipes which convey the gas, no accident can possibly happen from that quarter; because the gas which passes through the whole range of pipes sustains a pressure equal to the perpendicular weight of about one inch of water only, and such a weight of course is insufficient to burst iron pipes. Nor could the town when illuminated by gas-lights, be thrown suddenly into darkness, as has been asserted might happen by the fracture of a main pipe, supposing such an event should take place; because the lateral branches, which supply the street-lamps and houses, are supplied by more than one main; and the consequence of a fracture would be only an extinction of the few lamps in the immediate vicinity of the broken pipe, because the rest of the pipes, situated beyond the fracture, would continue to be supplied with gas from the other mains, as will become obvious from the sketch exhibited in the next page. [Illustration: Main pipe, leading from the Gas-light station or apparatus, situated in Brick Lane, near Old St.[34] Main pipe, leading from the gaslight apparatus, or station, at Norton Falgate.[35] Main pipe, leading from the gaslight apparatus, or station, in Westminster.[36]] [34] _The gasometer at this place is equal in capacity to 22000 cubic feet._ [35] _The capacity of the gasometer here is equal to 15928 cubic feet._ [36] _At this station the gasometer is equal in capacity to 14808 cubic feet._