BLUE LIMESTONE. 97 



would term them coal measures, or coalfields; but the coal beds .which 

 they contain are too inconsiderable to give name to the whole range. 

 If we allot them a particular designation, they ought to be termed The 

 alum hills; for the great beds of aluminous schistus form their most 

 distinguishing feature. 



The outline of these hills differs greatly from that of the oolite 

 chain. They have, indeed, generally speaking, a gentle declivity 

 towards the south, and abrupt cliffs towards the north; but their 

 summits instead of being flat are rounded, and their exterior or north- 

 ern faces, instead of being smooth, and forming a regularly inclined 

 plane, are rugged and broken. In many of their northern fronts, we 

 find, not far from their summits, a precipitous or steep cliff, of sand- 

 stone; from the foot of which, the shale beds form a declivity more 

 or less gentle, descending to the valley or plain below. Sometimes 

 we find two or more steep cliffs, with gentle slopes in the intermediate 

 spaces; and it is not uncommon to find the slope between two preci- 

 pices, or steep descents, forming a terrace of great extent, in front of 

 the higher part of the hill, which in that case exhibits the appearance 

 of one hill piled upon another. The lower precipices are sometimes 

 formed of the beds immediately over the alum shale, and sometimes 

 of the hard beds that proti-ude through it. 



The alum hills are of great extent, constituting the principal part 

 of the Eastern Moorlands of Yorkshire. They may be divided into 

 three ridges or chains, running parallel to one another, from east to 

 west; all commencing from the shore on the east, and all terminating 

 in some part of the plain of Cleveland on the west; but differing much 

 in length, breadth, and height; the most southerly being in all these 

 respects the greatest, the middle chain holding the next rank, and 

 the most northerly being the least. The first, which comprises the 

 highest land in our district, commences with the Stainton Dale clifis, 

 the high promontory called Peak, and the Fyling hills; and terminates 



2 B 



