l6 PHILOSOPHICAL TRANSACTIONS. [aNNO 1791. 



whinstoiie, except sometimes wlien the latter is interjected between the strata, of 

 squeezed up through fissures. In Wales the country is so hilly, that the lime- 

 stone, if it existed, has probably been washed away; but on the confines of Eng- 

 land it comes in. The road from Welchpool to Shrewsbury passes over the side 

 of the Long Mountain, which consists of schistus ; on the left, or towards the 

 east, rise some considerable basaltic hills. The strata of the Long Mountain 

 point towards the summit of these hills, as if the narrow valley that intervenes 

 had been cut by water on the lifted edge of the schistus. At a small distance 

 from the north and south sides of the basaltic hills calcareous strata are found. 

 Beyond Shrewsbury, on the road to London, we have, instead of the continued 

 ridges of Wales, a number of insulated, and generally rugged, points, rising 

 over the face of Shropshire and the adjacent counties. Were the plains covered 

 with water a few yards in depth, these eminences would appear from distance to 

 distance like so many stepping stones. They all, except the Malvern Hills, which, 

 though composed of granite, he considers as part of the same system, consist of 

 whinstone. Among these stepping stones he reckons the basaltic hills near 

 Welchpool, the Wrekin, Lilleshall Hill, and, at a greater distance towards the 

 East, the rising grounds near Newcastle in Staftbrdshire, whence the whin rock 

 jjerhaps communicates by the toadstone of Derbyshire, through the hills in the 

 North of England with the whinstone towards the South of Scotland. In a south 

 or south-west direction from the Wrekin, a number of craggy eminences arise. 

 They are basaltes, and form a striking contrast with the smooth, rounded, and 

 lumpish swells of schistus in their neighbourhood. From the whin rocks near 

 Stretton we may pass by the Brown and Titterstone Clee Hills (on the latter of 

 which are regular prismatic columns) to the Malvern Hills. About these hills 

 lie strata of schistus and limestone, as is seen on the road from Much Wenlock 

 to Stretton. To the south-east an extensive field of whinstone, with occasional 

 elevations, is spread over the confines of Worcestershire, Warwickshire, and 

 Staftbrdshire. Here we have the Rowley ragstone. Whether the basaltes pro- 

 ceeds southward by such interruptions till it join the Elvin or whinstone, and 

 granite of Devonshire and Cornwall, where probably they may be found incor- 

 porated, he wishes for an opportunity to examine. In I he plain part of this 

 whole district, the whin rock appears often at the surface, or a little below the 

 strata, so that the hills have probably a subterraneous communication with each 

 other, and there needed but a little more lifting force to form continued ranges 

 of mountains. The road from Welchpool to Birmingham, above 6o miles, is 

 repaired in a great measure with whinstone. A colonnade of basaltes has been 

 lately exposed in digging the Shropshire canal ; and in the mining country around, 

 levels have been driven in the black rock, as it is sometimes called. As whin- 

 stone and slate are seen in various other parts of North and South Wales, the 



