APPENDIX. 



731 



Bog Mine 

 Snailbatch 

 Grit and Gravel 



Tons of Lead. 

 .. 1554 



1300 



685 



Total of Shelve Mines. , 3,539 



Mr. John Taylor informs me that the present produce of lead in the United Kingdom may amount to from 

 47,000 to 50,000 tons. 



We thus see that the little Shropshire tract on which I have previously dwelt with so much geological interest, 

 has hitherto produced a thirteenth or fourteenth part of the total produce of the British Lead Mines. The ore 

 is of very superior quality, for at the Bog Mine each ton produces fifteen hundred weight of lead, and at the 

 Snailbatch, Grit, &c, about fourteen hundred weight ; while the average of the kingdom may perhaps be 

 estimated at not more than thirteen hundred weight. 



The reader who seeks for more information concerning the former condition of the Snailbatch Mine, will find 

 an instructive short sketch of it in the memoir of Mr. A. Aikin, " On the Occurrence of Witherite or Carbonate 

 of Barytes" in the vein-stones of that mine. (Geol. Trans., Old Series, vol. iv. First Series, p. 438.) The 

 vein of lead ore at that period (1811) varied from twelve to thirty feet in dimensions, and the greatest 

 depth of the works was one hundred and eighty yards. 



I possess little information concerning that mine, although I have often examined the features of the surface 

 around it. 



Of the Bog and Grit Mines I met, I have already spoken (as much as seemed needful for geological purposes) ; 

 but as my friend Mr. Joseph Walker, one of the proprietors of the Bog Mine, has offered me information 

 which I did not possess when the chapter on that tract was printed, I willingly add the following extract of a 

 letter to him from Mr. W. Jones of Chester. 



" The present depth of the Bog engine-shaft is 293 yards, and the lowest level 265 yards. In the upper 

 workings, above the adit or boat-level, which is 105 yards deep, there are three distinct veins to the eastward, 

 but two of these unite at about ten fathoms under the adit level. Thus united, they are crossed about the 

 middle of the mine by the other vein, which in the upper part of the mine, or towards the Stiperstones, is 

 called the ' South Vein,' and to the west, after it has crossed the other vein, will consequently be on the north 

 side. The main vein is from 2 to 3 feet wide, and the other, which crosses it, from 6 inches to 1 foot. The 

 two branches of the main vein not only join each other on the line of bearing, but hade towards each other 

 and unite downwards, so that at the 20-fathom level and below we have only two veins. We have pursued 

 this level within about 250 yards of the Stiperstones, but the work has been suspended for some time in con- 

 sequence of the vein being very small and poor. I know of none of the veins in this country that have been 

 •worked up to the Stiperstones, but I have little or no doubt that they do not break through them, though 

 undoubtedly the Snailbatch vein has been found on the other side of the Stiperstones, but whether in a 

 continuous line, or thrown on one side, I am not prepared to say." 



Those who have perused my chapter on this tract will have perceived, that I spoke of some of the lead veins 

 having been worked up to the flank of the Stiperstones, where they were found to be deflected and cut off. I 

 had this information from an old miner, and I have no doubt that my general view in supposing the Stiper- 

 stones to be a great wall or rider bounding this mining tract on the east- south- east is substantially correct. 

 That a small branch or poor vein of lead should have been found (in a shifted position) on the eastern side of 

 the Stiperstones near Snailbatch, is by no means remarkable, but rather in analogy with many examples in 

 other tracts. See account of the Cerrig-mwyn mines, p. 366. As a matter of fact, it is, however, well known 

 that there is no other trace of a lead vein (however small) in the Linley, Pulverbatch, and Longmynd Hills to 

 the east and south-east of the Stiperstones, while copper veins are there in abundance. I therefore adhere to 

 my original position, leaving chemists to speculate on it, — namely, that in a tract highly convulsed by volcanic 

 action there are two distinct metalliferous tracts, neatly separated from each other by a wall of quartz rock, 



