138 Mr. Hatchett'j Obfervalions on Bituminous Siibftanovs- 



BITUMINOUS WOOD, as well as of TURF and PEAT. 



Bituminous or FofUl wood is found in many places ; bat in re- 

 ipcot to that which is found at Bovey, near Exeter, and which is. 

 therefore called Bovey coal, there are fome peculiarities which de- 

 ferve to be mentioned. The Bovey coal is a dark brown, light, 

 brittle iubftance, which in texture and other external properties 

 much refembles wood which has. been half charred. It is not 



:nd as fcattered logs or trunks, but forms regular ftrata. 



The pits are on a heath which is flat and Tandy ; the ftratum of 

 fand is however but thin, after which a pale brownifh grey clay is 

 found mixed with quartz pebbles. This prevails to about fix feet, 

 at which depth the firft ftratum of the coal commences. The 

 quality of this is however much inferior to that of the fubfequent 

 ftrata, which in all amount to feventeen, producing a depth of 

 nearly feventy-four feet from the furface. Between each ftratum 

 of coal is a ftratum of clay. The direction of the ftrata is fromeaft 

 to weft, and the inclination or dip is from north to fouth. The 

 inferior ftrata are thought to afford the beft coal, and the coal is 

 more folid and of a better quality towards the fouth. The thickeft: 

 ftratum of coal is from fix to eight feet*. 



The Bovey coal burns readily with a flame like half charred wood": 

 it does not crackle, and, if but moderately burned, forms charcoal; 

 or if completely burned, it leaves a fmalf quantity of white afhes 

 exactly ftmilar to thofe of wood. The fmell of it when burn- 

 ing alio refembles that of wood, with a faint difagreeable odour. 

 It is certainly very remarkable that this fubftance fhould form 

 regular ftrata, although it poffeffe* the texture and moft of the 



* In the winter, twelve men can raife about j 20 tons of this coal in a week, the 

 *dkile. of which is employed in a neighbouring Pottery. 



proptrtiei 



