188 A Ramble in West ShropsM 



re. 



extent, the configuration of the land where they were deposited. 

 Similar deposits are occurring at the present day, and give 

 us a clue to the conditions under which these early ones were 

 formed. Reasoning thus, we may conclude, when we find a 

 conglomerate, that we are in the immediate neighbourhood of 

 some ancient sea beach or estuary, or that this was the site of 

 some vast river or mighty current ; stones such as those 

 which are found in it, are never carried out to any great 

 distance from the land. In this conglomerate, moreover, may 

 be remarked a very striking instance of that slow but im- 

 mensely powerful process by which change takes place in the 

 very substance of the materials of which the earth's surface is 

 composed. It is in several places traversed by veins of quartz 

 running right across the strata in direct lines, so as to traverse 

 even the substance of the pebbles which lie in their way. It 

 is easy to conceive a crack occurring in a solid rock, and to 

 suppose quartz infiltrated therein, but such a supposition can- 

 not be admitted here, there is no appearance whatever of any 

 fissure by which these pebbles could have been divided, and 

 yet, where they lie in the course of the line of quartz formation, 

 a portion of their substance has become quartz. It is clear 

 that here we perceive evidences of a kind of chemical action 

 taking place in a certain plane, and suggests to us that, on a 

 larger scale, the same may account for many of those effects 

 which have been too frequently ascribed to igneous and volcanic 

 action, in default of any known cause, just as it is tbe custom, 

 among those who are quite ignorant of the laws of electricity, 

 to attribute to it every unaccountable phenomenon. • 



But it is time for us to wend our way westwards to the 

 Stiperstone range — hills of considerable height running parallel 

 with the Longmynd. This ridge is considered, by Sir R. 

 Murchison, to be the representative of the Lingula flags of 

 North Wales, and the lowest member of the Silurian group. 

 Its most marked physical feature is the existence at intervals 

 along its summit, for a distance of ten miles, of huge masses 

 of rock protruding from the surface to the height of twenty or 

 thirty feet. These rocks, being quartzose, and very much 

 harder than the surrounding strata, have resisted more effec- 

 tually the action of the atmosphere, to which the whole has 

 been exposed since its emersion from the ocean, and there 

 they stand like gigantic fortresses, grey and ribbed with*age, 

 looking down in lonely majesty on the silent, ceaseless decay 

 of all around; adding, too, their own contributions to the 

 general ruin, as is testified by the masses of rock torn from 

 their sides by many a frost, and which lie beneath them on 

 the flanks of the hill. 



Sir R. Murchison has observed that there are several 



