732 



APPENDIX. 



which I have shown to be sandstone fused and altered by heat. — (See Note, p. 8, on the origin of the word 

 Stiperstones.) 



In relation to the " warm water vein" of lead ore in the Shelve district, (see p. 280), I am informed by Mr. 

 Joseph Walker, that, upon re-opening the works to follow that vein, he convinced himself from actual exami- 

 nation that the water was there much hotter than in any other part of the mining ground. He also 

 observed much mineral pitch or bitumen in the vein stuff and on the sides of the vein. Any doubts, therefore, 

 which might have existed as to the presence of bitumen in these old rocks is entirely dispelled. There is 

 much trap and altered rock around this spot, and the phenomenon is therefore confirmatory of my views, 

 p. 276. 



The rugged tract of the Corndon and Shelve Hills will be rendered doubly attractive by the forthcoming 

 work of the Rev. C. H. Hartshorne, alluded to p. xxxii, in which the reader will find an account of Druidi- 

 cal circles, Stones of worship, &c, on Stapeley Hill and at the foot of Corndon. 



F. (2.) 



Heblands, near Bishop's Castle. 



Through inadvertence a point of trap rock which bursts through the Silurian strata at about one mile N. 

 of Bishop's Castle has not been mentioned in the text, though I have twice examined it in former years. It is 

 a hard, whitish, compact felspar rock, the eruption of which has altered the contiguous strata to some extent, 

 giving rise to coats of impure serpentine, veins of calcareous spar, crystals of iron pyrites, breccia, and indurated 

 schist. It is marked upon the map, and may be considered as the extreme southern point of the volcanic tract 

 of Shelve or Corndon. 



F. (3.) 



Mines of Gogo-fau, Caermarthenshire, and Gogo, Salop. 



I have to thank the Rev. H. C. Hartshorne for having directed my attention to a letter in the Cambrian and 

 Caledonian Quarterly Magazine, vol. v. p. 321, in which the late Mr. T. Parker describes the Roman Mines 

 of Gogo-fau (see p. 367). It appears that this author detected a few traces of galena, and therefore he con- 

 cluded that " lead was the substance sought after ; but from the unconnected irregularity of the works, one part 

 having scarce any reference to another, it must," he says, " be considered as a bunching mine, which in some 

 degree accounts for the wideness of the excavations, and that so soon as one bunch or mass of ore was cleared 

 away they broke the ground in all directions in search of another, finding no string or metallic leader, as in 

 more regular mines, to guide their course." 



Again, in a learned historical inquiry into the situation of the gold mines of the ancient Britons, the mines 

 of Gogo-fau are also described (Cambrian Register, vol. iii. p. 41), and the author states, that Sir Joseph Banks 

 and several other persons who visited these caves or galleries were of opinion that they had been worked for 

 gold. The reader will there find a good explanation of the manner in which the water was conducted to 

 stream the works in question, and some ingenious speculation on the antiquities, both British and Roman, 

 around Cynfil-Caio, with aversion of the legend of the Five Saints (Llan -pump -Saint) differing from that which 

 I have given. 



In his excellent statistical account of the parish of Llanymynych, (Cambrian Register, vol. i. p. 265,) the 

 Rev. Walter Davies gives some curious information respecting the great mine of the Ogo, which runs from 

 West to East, in the promontory of Carboniferous limestone before described (see p. 145), and which is 

 clearly proved to have been a Roman work from the remains found within it. Besides various ores of copper 

 and lead, Mr. Davies alludes to calamine and blende as of occasional occurrence, but states that the mines 

 are now exhausted of their wealth. 



