<J2 



THE GEOLOGIST. 



the seam has, owing to the decomposition of the iron, a reddish- 

 brown appearance ; and, where sufficiently rich in iron, shows the 

 usual " scrappy" layers, or envelopes, owing to the percolation of 

 water. This is very noticeable at Fryup Head, where the seam is of 

 great thickness. 



I now pass upward to the "bottom sandstone rock," of winch I spoke 

 before, and which is the great and safest guide in searching for the iron- 

 stone strata. It runs along the summits of the sides of most of the 

 Cleveland dales, and has been used very generally in the district 

 for building purposes. At Sleights, near Whitby, it has been exten- 

 sively wrought for local use, as also for shipment, and is in fact the 

 great building stone for the whole of Cleveland. It caps most of the 

 chief hills, or " banks," as they are called in the district, crowning the 

 summit of Roseberry Topping, Easby Bank, &c. The excellent state 

 of preservation of the stonework in the ruins of Guisborough Abbey, 

 and Mount Grace Priory, attests the durability of the rock. 



I now come to the next division in my section (/), which it would 

 be difficult to subdivide in such a manner as to be equally applicable 

 to all parts, where the rocks contained in it crop out to view. Above 

 the bottom sandstone rock, however, are alternations of shales, thin 

 iron-bands, and gritty sandstone layers, about sixty feet in total thick- 

 ness. We then come to a vast series of sandstones and shales of 

 various colours and thicknesses, and amongst them are some seams 

 which demand a short notice. In this series we find a variable stratum 

 of fire-clay, which is well seen in the excavations of a recently-formed 

 Eire-clay Company at Skelderskew, in Commondale, where it is of 

 considerable thickness, and, it is also stated, of great commercial 

 value. Embedded in an impure sandstone bed above this seam are 

 found vertical Equisetites, in great abundance — the Equisetum cohim- 

 nare. Higher up, amidst the countless beds of shale and sandstone, 

 we find a thin seam of coal, of sufficient importance however to be 

 worked for local use, although the thickness is never more, and some- 

 times a few inches less, than sixteen inches. This seam, which is 

 accompanied by fossil plants in the shales above and below, is similar 

 to one discovered in the same oolitic series of Brora, in Scotland, and 

 worked from the patriotic — certainly not pecuniary — motives of a late 

 Duke of Sutherland. In the North Yorkshire district it is worked 

 at Bosedale Head, Danby End, and, until recently, at Great Eryup 

 Head. It may be seen out to the day on the side of the road from 

 Castleton to Guisborough, about half a mile from the former place ; 

 and in the hill as you ascend to Danby Beacon from Howlsike. An 

 acre of this moor-coal is generally estimated to contain about two 

 thousand chaldrons of thirty-two bushels. The appearance of this 

 carboniferous deposit has not failed to excite hopes in some whose 

 scientific knowledge, it need hardly be said, is like the coal-seam — 

 limited : that by going further down, better, or — as some even think 

 — the Durham coal-seams will be discovered. Although men seem 

 born with the "only-go-deeper" notion in their heads, it seems un- 

 necessary to remark, that any hopes of finding coal superior to that 



