GEOLOGY OF PART OF SOUTH DURHAM. 151 



the country beyond. A few miles to the east the Coal Measures 

 are overlaid by the Magnesian Limestone. Our remarks at pre- 

 sent chiefly relate to the Coal Measures. 



We may remark that this portion of the Durham coal-field has 

 long been noted as a colliery district, as well as for the good 

 quality of its coal. As far back as the twelfth century there is 

 evidence of coal being wrought here. Long after that, though 

 still far back from the present time, the collieries on Cockfield 

 Fell, and those about Etherley and other places near, were in 

 full operation, producing coal not only for South Durham, but 

 for a very large portion of Yorkshire. This was long before 

 the era of railways — even before that of good roads of any 

 kind, for much of the coal was carried away on pack-horses, 

 as well as in carts and waggons, as far as Lofthouse, Guisbo- 

 rough, Ripon, and other places as distant. The method of 

 getting the coal was just as primitive as its mode of transit. 

 There were no deep sinkings. So much, indeed, of the coal lay 

 near the surface, that there was no need to go far for it. A 

 round hole four or five feet wide (sometimes scarcely that), and 

 a few fathoms deep, would " win" the coal : a gin, and perhaps 

 an old blind horse or a donkey, a piece of hempen rope, a few 

 dozen hazel corves, and a barrow or two would be plant enough 

 to work it. When the coal near the shaft was got and the draw- 

 ing below became troublesome, a new pit would be sunk to win 

 a fresh patch of coal. So often would this be repeated, that we 

 have seen a field of a few acres with almost a score of these old 

 pits in it. At a later period, when the easiest got coal began to 

 be exhausted, deeper pits were sunk, engine power of a simple 

 type was introduced, and a little more systematic mode of work- 

 ing adopted ; but by this method probably not more than a third 

 of saleable coal would be got from the seam, the remainder being 

 left below as pillars or as dross, or burnt at bank in great mounds 

 or "pit heaps" of small coal. Later still railways opened out 

 the country ; and yet more recently, the iron- ore of Cleveland 

 was discovered — events which effected a wonderful change in 

 the coal-trade of this district, greater perhaps than in any other 

 portion of the coal-field. For, within a short time coke became 



