118 DESCRIPTION OF THE STRATA. 



strata consequently swell into a greater thickness, the coal seams are 

 more considerable, and haA^e been wrought for 70 or 80 years. This 

 is particularly the case at Blakey and Rudland, in the first range of 

 our alum hills ; and at Danby or Castleton, in the second. The great- 

 est thickness of coal is at the Danby pits, where the seam is 1 7 inches. 

 The depth from the surface varies from 15 to 60 yards. The quantity 

 of coal obtained here, may be about 200 or 300 bushels per day, on 

 an average. The other works are less extensive. At the Blakey pits, 

 the seam is about 12 inches ; and at Rudland, it is only 9 inches : but 

 at both places, the depth from the surface is usually less than at 

 Danby. A new coal work has commenced at the head of Fryop, 

 where the seam is about 16 inches, and the depth from the surface 

 18 yards. Another work was lately carried on at the upper part of 

 Glazedale; and there is one also at Maybecks on the Sneaton estate, 

 where the seam is 6 inches. Above 30 years ago, there was coal 

 obtained at Allen Tofts in Godeland, where the seam was above two 

 feet thick, being the greatest known in this district ; but this was found 

 to be merely an accidental swell of the coal stratum, which was soon 

 exhausted. In almost all these spots, the seam wrought is one of the 

 uppermost in the series, being not far below the blue limestone. The 

 seam wrought at Maybecks, like that at Cloughton wyke, is only a few 

 yards beneath the limestone. 



As the blue limestone passes through the Hambleton hills, and 

 appears in the valleys beyond them, so also does the coal. It has 

 been found at Coxwold, not many yards below the blue limestone. 

 Here a coal work commenced 16 years ago, and was continued 10 

 years. The seam was about 12 or 13 inches, where it was thickest; 

 the depth from the surface varied from 7 yards to 29 yards, the seam 

 having a rapid dip towards the north-west. The covering here, as at 

 the pits in our alum hills, consists of sandstone and shale, the latter 

 containing hard nodules. 



