VOL. XXXIII.] PHILOSOPHICAL TRANSACTIONS. Jig 



fire-Stone; whereas the latter is always found in those mines, contrary to the 

 works in Staffordshire, Newcastle, and Scotland, where freestone does lie 

 over the coal. He further observed the strata of stone, clay, and marl, of 

 the interjacent hills, where, under the black marl, lies a spongy yellowish 

 earth; all this lies above the red soil, which is generally the surface of the 

 vallies, where the coal is found. And as this red mould on the surface dege- 

 nerates into marl or loam, so towards the north west, beyond or without 

 the veins of coal, about Winford, in the same county, it turns to ruddle, or 

 red-ochre, used chiefly for marking sheep, and for ground colours or priming, 

 instead of Spanish brown; and often counterfeits bole ammoniac. 



But as he never heard that any coal was found to the west or south 

 of Mendip hills; so Cotswold, to the north-east, and the Chalk-Hills of Marl- 

 borough-Downs and Salisbury Plains, seem to set bounds to the coal country, 

 to the east and south-east; of which fig. 3, pi. 2, may be supposed a section from 

 south-east to north-west, viz. from the dip to the rise ; and fig. 4, at right 

 angles, from south-west to north-east, on the drift or level. 



Mr. S. mentions this by way of correction and addition to his former ob- 

 servations of the coal-works in Somersetshire. He has since had opportunities 

 of being under ground, and viewing several coal-works in Scotland and Nor- 

 thumberland, and observing their several strata. At Widdrington they have 4 

 fathom clay, then a seam of coal, about 6 inches thick, not worth working; 

 then a white freestone ; then a hard stone, called whin ; then 2 fathom of 

 clay; then a white soft stone; and under that a vein of coal 3 feet Q inches 

 thick. This is a small coal of the same nature, but not so good as the 

 Newcastle coal which comes to London market. These veins dip to the 

 south-east, one yard in 20. Near Tranent, in East-Lothian in Scotland, the 

 coal dips also to the south-east, in the same proportion ; but at Baldoe, in 

 the parish of Campsy, 3 miles from Kylsith, it dips to the north-east; and at 

 Madestone, near Falkirk, to the same point, and in the same proportion. 

 The strata of earth sand minerals, at these places, agree very nearly : they have, 

 as the ground rises or falls, 1, 2, or 3 fathom of clay; then Jl fathom of 

 slate, or coal-clives ; 1 fathom of limestone ; under that 2 fathom of slate, 

 earth and stone ; and then coil. And all these agree in this, that the pits 

 generally need no timber, and have a good roof, which is supported by pillars 

 of coal, which they leave in the working. At Baldoe, the coal is commonly 

 45 inches thick ; and all along, for some miles eastward thence, on the sides 

 of the hills, are crops of coal and limestone; and the tenants often spit up as 

 much as will serve them for a winter's burning, just under the surface ; for 

 there wants a market, and it is scarcely worth working for sale. And to the 



