Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/78

 not to be found, though the seams cannot be compared in magnitude to those of the Newcastle formation. In the mountainous parts of the district the seams are extremely limited in extent, being soon squeezed out, as the miners term it, and seldom exceeding 20 inches in thickness. In the high grounds, near the sources of the South Tyne and the Allen, Coarse or Grow coal abounds; and on Aldstone moor five seams of this fossil are imbedded between the grindstone sill and the Tyne bottom limestone: it does not appear among the sills on the Derwent towards the Cast, or of Dufton towards the west of Aldstone, but occurs near the summit of Cross Fell, where no other is to be met with. Crow coal generally rests upon a thil or plate of slate-clay; but the beds being very uncertain in their extent are seldom noticed in the Lead-mine sections. They are worked at a small expense by means of drifts into the sides of the hills, and as fuel is scarce in the mountainous district, Crow coal becomes an object worthy of attention.

This mineral is of a dirty sooty-black colour, and contains much sulphur, which renders its smoke extremely offensive. At Aldstone it is mixed with clay and made up into balls, which yield considerable heat on burning, but emit scarcely any flame.

On leaving the mountainous district, the seams of coal are found improved in point of quality and thickness, and it will appear from the following localities, over what an extent of country that mineral is found.

It occurs at Stublick, six miles south-west of Hexham; at Wall near Fallowfield; near Bellingham on the North Tyne, where many good seams are found; at Kerryburn near the foot of the Carter on the borders of Roxburghsbire; in the vale of the Reed; at Elsdon; at Woolcoats on the moors near Harbottle castle; at Hesleyhurst; at Healy-coat; near Carlington castle; at Newton; at Shilbottle;