e 
16 Iliumination by Coal Gas. (Jury, 
ArtTic.e IV. 
On the Method of Illuminating the Streets by Coal Gas. 
By Mr. Frederick Accum, 
(To Dr. Thomson.) 
SIR, 
Your Correspondent in the Annals of Philosophy for April, 
p- 313, who appears to be alarmed concerning the safety of the 
application of the gas light illumination, and is desirous of obtain- 
ing information concerning certain facts relating to the scheme of 
procuring light by means of carbureted hydrogen, or coal gas, is 
hereby informed that the explosion he alludes to was occasioned in 
consequence of a quantity of coal gas having been suffered to enter 
into the building where the gazometer was erected, and where it 
mingled with common air, and was set on fire by the approach of a 
lighted candle. I give this statement from a letter before me, 
written by the proprietors of the establishment at whieh the acci- 
dent happened to a Gentleman in this town. They who are familiar 
with thesystem of lighting with coal gas will readily allow that gas 
light illumination is more safe than the illumination by candles or 
lamps. Asa proof of this statement, it need only be mentioned 
that the fire-offices engage themselves to ensure cotton-mills and 
other public works at a less premium where gas lights are used than 
in the cases of any other lights. In fact no danger can arise from 
the application of gas lights, in any way but what is common to 
candles and lamps of ‘all kinds, and is the fault of none of them, 
Even in this case the gas lights are less hazardous. There is no 
risk of those accidents which often happen from the guttering or 
burning down of candles on carelessly snuffing them. ‘The gas 
light lamps and burners must necessarily be fixed to one place, and 
cannot fall, or otherwise become deranged, without being imme- 
diately extinguished. Besides, the gas lights emit no sparks, nor 
are any embers detached from them. And with regard to the pro- 
duction of the gas, it is certain that the manufacture of coal gas is 
a process perfectly safe. ‘There is no more risk in the action of a 
gas light machine properly constructed than in the action of a steam 
engine built on just principles. No part of the machinery is liable 
to be out of order. There are no cocks to be turned ; no valves to 
be regulated; nor can the operator derange the apparatus but by 
the most violent efforts; and when the stock of gas is prepared we 
may depend as much on its lighting power as we depend on the 
light of a certain number of candles or lamps. To obtain this gas 
the workman is not called upon to exercise his own judgment: it 
requires nothing more than what the most ignorant person, with a 
common degree of care and attention, is competent to perform. 
