156 COMMON COAL. 
it yields is peculiarly brilliant and beautiful. It was at 
the foundery belonging to Messrs. Boulton and Watts, 
at Birmingham, that the first public display of gas lights 
was made, in the year 1802, on the occasion of the re- 
joicings for peace. In 1805 the cotton mills of Messrs. 
Phillips and Lee, at Manchester, were lighted with gas, 
to the exclusion of lamps, candles, and every other 
source of artificial light. In the beginning of 1816 it 
was estimated that, at the three gas-light stations, in 
Peter-street, Westminster, Worship-street, and Norton 
Falgate, London, twenty-five chaldrons of coals were 
used daily ; and that these were sufficient to supply 
with gas 125,000 large lamps. At the works in Dorset- 
street, Fleet-street, the daily consumption of coal was 
about three chaldrons, which afforded gas for 1,500 
lamps. 
The production of the gas light is easily effected in 
miniature, by putting common coal, pounded small, 
into the bowl of a tobacco-pipe, and closely covering 
this with clay made into a stiff lute with water. 
When the clay is dry, the bowl of the pipe must be 
put into the fire, and there heated gradually. In a 
few minutes a stream of gas will issue from the end of 
the pipe* This may be set on fire with a piece of pa- 
per, and will burn with a bright flame. When the gas 
is no longer disengaged, there will be found in the 
bowl of the pipe the remains of the coals, in the form of 
coke. 
It is estimated that one chaldron of good coals will 
afford from 17,000, to 20,000 cubical feet of gas ; and 
that one of the large burners in the shops of London, 
consumes about four cubical feet per hour. 
Soot is produced from the smoke of burned coal, and 
is used as a manure for cold, moist, and clayey mea- 
dows and pastures : and pounded coal has been applied 
to the same purpose in some parts of the Continent. 
By a process called charing, coal is divested of its hu- 
mid, acid, and bituminous particles, and is converted 
into a kind of cinder called coke. This is employed in 
