1824] 
balanced. The only question, with the 
manufacturer, being the price which can 
be obtained for either kind of gas’ from 
the public, : 
It is obvious that this pomt could not 
be determined @ priori. The public are, 
in all cases, slow to adopt any novelty, 
requiring experimental proof of any pro- 
fessed advantages previous to the adop- 
tion of any new arrangements. Hence, 
on the first. introduction of gas for 
street-lights, the heads of parishes or 
districts were not' disposed to pay any 
additional price for gas-lights, beyond 
what they had previously allowed for 
oil lamps, whatever advantages the new 
plan might have possessed over the old 
system. And it is a well-authenticated 
fact, that, in order to induce the dif- 
ferent. parishes of the metropolis to 
give gas-lights a fair trial, the principal 
gas companies undertook to light the 
public or parish lamps, at a lower rate 
than could afford them a remunerating 
price; and, I apprehend, even at the 
present day, the price at which they 
contract to light the public lamps would 
be a ruinous speculation to the coal-gas 
companies, but for the great number of 
private lights supplied from the same 
main pipes. The interests of these gas 
companies, however, whether coal or 
oil, being a point on which they must 
be themselves the most competent 
judges, and their interest being in an 
Inverse ratio to that of the public, I 
shall proceed to examine the relative 
advantages afforded to the public be- 
tween the light from coal-gas and that 
from oil-gas. —- 
It has hitherto been almost the uniform 
practice with the coal-gas companies to 
furnish their customers with an unlimited 
supply of gas, during the period stipu- 
lated in each agreement; whilst those 
who have furnished oil-gas have very 
judiciously supplied it by meter, or 
measurement. This liberality of the 
_ coal-gas companies has however been 
attended with two disadvantages: it 
enables the consumer to defraud the 
companies of their commodity, whilst 
the jet of flame of a gas-light, when too 
far extended, always gives a diminution 
instead of an increase of light. 
No gas flame should ever extend above 
the top of the glass cylinder or globe ; 
for in such case the gas escapes without 
being consumed, and occasions the chief 
part of that disagreeable effluvium which 
is often observed in confined rooms 
where gas is used. 
This is a point well worthy the atten- 
Comparative Valueof Coal and Oil Gas. 
123 
tion of every one, as it regards health 
and cleanliness. For the effluvium is 
not only very noxious, more especially 
to asthmatic persons, but it deposits 
that carbonaceous matteron the ceiling 
or walls of the room, which ought to 
have been consumed'in the production 
of light. If a gas flame be kept within 
proper limits (that is, never to extend 
above the glass; or allowed to have a 
smokey top) it is certainly the cleanest, 
and by far 'the most convenient sub- 
stance we can have for giving artificial 
light. The coal-gas companies thus 
leaving the requisite quantity of gas’ to 
the discretion, or rather the indiscretion 
of the consumier, it is obvious that the 
waste of gas must be enormous from 
this source. The oil-gas companies, 
however, provide an effectual check 
against this improvident consumption of 
gas, by supplying their customers with 
a stipulated volume, instead of an un- 
limited quantity, as given by the coal- 
gas proprietors. 
This is undoubtedly the most equitable 
plan between both parties, provided the 
actual value of the commodity is ascer- 
tained, and guaranteed to the consumer: 
for if the consumer burn the gas waste- 
fully the loss will fall upon himself; 
while the durability of the lights will 
be, in all cases, in proportion to the 
density or real value of the gas. 
From the first introduction of inflam- 
mable gas for artificial lights it has been 
observed that the illuminating power 
given out from a jet of carbutted hy- 
drogen, is in proportion to the density 
of the gas; or in other words, as the 
quantity of carbon in combination with 
the hydrogen gas. ve 
Hydrogen alone, being burnt in the 
atmospheric air, affords a feeble reddish 
flame; but as it becomes charged with 
carbon the flame assumes the various 
hues of orange, yellow, straw-colour, 
and white. A saturated solution of 
carbon in hydrogen yielding a beautiful 
light of the purest white; such as the 
flame from wax or spermaceti, or the 
finer oils, and the best oil-gas. 
As the object of my present commu- 
nication, Mr. Editor, is rather a popular 
or practical view of the subject of gas- 
lighting, than a scientific enquiry, as to 
the constitution of the various com- 
binations of hydrogen and carbon, I 
shall be extremely brief as to the che- 
miecal view of the subject. 
Assuming the specific gravity of at- 
mospheric air to be 1,000, the density of 
the best oil-gas is about 960; and the 
RY hest 
