164 NOTES ON COAL AND FUEL. 
Great Britain must have been at a considerably higher temperature than 
at the present time ; and which vegetables must have been washed down 
by rivers probably in the form of forests, and deposited, together with 
sandstone, clay, limestone, &c, in the situations where we now find coal. 
The question then arises, from whence did the mass of vegetable matter 
come ? — was it supplied by forests in any part of our own island ? — or 
was it obtained from land now beneath the sea, in the Northern and 
Western oceans ? It is called " pit coal," from the circumstance only of 
its being obtained from mines and pits ; and in London, for no better 
reason than its having been conveyed thither by sea, it has the name of 
" sea coal." 
Its uses as fuel are too extensively known to need here any observa- 
tions. By the distillation of coal, an inflammable gas is produced. The 
gas is conveyed by pipes, from the reservoir in which it is collected, to 
great distances ; and the light which it yields is peculiarly brilliant and 
beautiful. It was at the foundry belonging to Messrs. Boulton and 
Watt, at Birmingham, that the first display of gas light was made, in 
the year 1802, on the occasion of the rejoicings for peace. In 1805, 
the cotton mills of Messrs. Philips and Lee, at Manchester, were lighted 
with gas. In the beginning of 1816 it was estimated that, at the three 
gas-light stations, in Peter street, Westminster, and Worship street and 
Norton Folgate, London, twenty-five chaldrons of coals were used daily ; 
and that these were sufficient to supply with gas 125,000 large lamps. 
A ton of coal makes between nine and ten thousand feet of gas, and 
a saleable chaldron of coke. The same quantity loses in the act of 
carbonizing (if weighed hot) about 30 parts out of a 100 ; so that 70 parts 
is the quantity of coke left in the retort. Of the 30 parts, 15 are gas, 
1 tar, 5 water, and 5 are consumed by purification. 
With respect to the illuminating power of ordinary coal gas, it is 
estimated that five feet are equal to twelve mould candles, of six to the 
pound weight. 
Cannel Coal is of a black colour, with little lustre, is not laminar, 
but breaks in any direction, like pitch, and does not stain the fingers. 
It burns with a clear flame resembling a candle. It is rather heavier 
than water. 
This highly inflammable kind of coal is found abundantly in the 
neighbourhood of Wigan, in Lancashire, where there is an entire 
stratum of it about four feet in thickness. It is also found near White- 
haven, in some of the pits at Newcastle, and in some parts of Scotland. 
Doubts have been entertained respecting the name of this coal ; but 
when it is recollected that in Lancashire, whence it is chiefly brought, 
the word candle is usually pronounced with the omission of the letter d, 
and that, in many instances, the coal is used by the poor as a substitute 
for candles, these will be immediately removed. In Scotland it has the 
name of "parrot coal." 
Stone Coal, Kilkenny Coal, Welsh Coal, or Glance Coal, is of a dark 
