Читать книгу Description of the Process of Manufacturing Coal Gas. For the Lighting of Streets Houses, and Public Buildings онлайн

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All the varieties of coal used in this country for fuel may be divided into the following classes.

The first class comprehends those varieties which are chiefly composed of bitumen only, which take fire easily, and burn briskly with a strong and yellowish white blaze, which do not swell or cake on the fire, and require no stirring, which produce no slag, and by a single combustion are reduced to light white ashes. Some of this species of coal when suddenly heated crackle and split into pieces, especially if laid on the fire in the direction of the cross fracture of their laminæ.

Cannel coal, deserves to be placed at the head of this class; next to this, we may rank all those descriptions of coal known in the London market by the names of Hartley, Cowper’s Main, Tanfield Moor, Eighton Main, Blythe, and Pont Tops. It also includes the sort of coals found in several parts of Scotland, called Splent coal, and some of those raised on the Western Coast of England.

Most of the coals raised in Staffordshire ought likewise to be classed among this species of coal, but the line of distinction between these, and the classes subsequently named, cannot be accurately drawn.