Greai Coal-Jield of Shropshire* 193 



vlties of the hills considerably steeper than the northern, and some- 

 times even quite precipitous, where they constitute the boundary of the 

 vallies of the Severn, and the other principal streams that flow through 

 it. None of these hills, in the Shropshire part of the district, exceeds 

 the height of four hundred feet above the level of the Severn at 

 Coalbrook-dale. Another circumstance remarkably characteristic of 

 this kind of sandstone, is the great number of meres^ or deep pools, 

 which it contains. The outline of all these pools more or less 

 approaches to circular : they receive no streams, and very often do 

 not transmit any, the loss by percolation and evaporation being nearly 

 supplied by the springs that occupy the middle and deepest part of 

 their bottoms ; I say nearly, because all that I have examined bear 

 evident marks of gradual diminution : in many, this change has 

 advanced so far as to convert the whole area, with the exception of 

 a deep pit or two near the centre, into a peat-moss, and some of the 

 smaller and shallower ones are not only entirely filled up, but are 

 even converted to the purposes of agriculture. The above characters 

 seem to identify this rock with the old red sandstone formation of 

 Werner. 



That portion of it which lies between the great coal-fields of Staf- 

 fordshire on the east, and of Shropshire on the west, is about twelve 

 miles wide. The Staffordshire strata dip tapidly towards It In a 

 western direction, while those of Shropshire decline towards it, at a 

 lower angle, in an eastern direction. Whether they actually pass 

 Under the sandstone, or terminate abruptly on coming in contact 

 with it, has not yet been demonstrated ;- many intelligent miners are 

 of the former opinion : but to me, the latter appears the more pro^ 

 bable, from an observation that was made a few years ago in Wei- 

 bach colliery near Shrewsbury. In this ooal-field, as in the two 

 before mentioned, the strata dip towards the sandstone j and there 



2b 



