S44 A Geognostical Sketch of [Nor. 



They have been wrought for some years by a Newcastle company, 

 I should conceive at an immense loss. These were the only lead- 

 mines in the country in which I saw steam-engines employed. At 

 all the others the, machinery is driven by water. 



There is a very remarkable north and south vein, which crosses 

 the country a little to the west uf Allenheads. I did not myself see 

 it, but obtained my information respecting it from Mr. Emersom, 

 one of Colonel Beaumont's principal agents at the Weardale mines. 

 It causes the beds on the west side to dip about 40 fathoms ; and, 

 what is remarkable, this dip is not instantaneous, but gradual. The 

 bedt slope down on the west side till they become 40 fathoms lower 

 than they are on the east side. 



Of the cubic galena, of which the lead ore here consists, there 

 are two varieties. The first, which is uncommon here, breaks into 

 large cubes with a smooth splendent surface ; the second, which is 

 almost universal, is apt to break into small cubes, the surfaces of 

 which are not flat, but waving, and the lustre is inferior. I was 

 informed by Mr. James Mulcaster, who has the charge of the 

 smelting-house belonging to the Greenwich Hospital, and who has 

 made many experiments on the subject, that the first of these 

 varieties always yields more lead than the second. It would be 

 worth while to examine whether the second variety contains any 

 antimony, or similar foreign body, which makes its escape during 

 the proee-s. 



According to the best information which T could procure, the 

 quantity of lead ore raised annually in this country (not reckoning 

 the Teesdale mines) amounts to 67,500 bings, or 540.000 cwt. ; for 

 a bing of ore weighs eight cwt. Now eight cwt. of ore yield at 

 an average 5i cwt. of lead.* Thus the whole of the lead annually 

 brought into commerce from the neighbourhood of Newcastle 

 amounts to 354,375 cwt. Were we to reckon this only at 30/. 

 the t'other (of 21 cwt.), the annual value would exceed half a 

 million sterling. + About one third of this enormous quantity of ore 

 is raised by Colonel Beaumont, to whom a great number of most 

 valuable mines belong, and who is the greatest miner in this 

 county, and perhaps in Great Britain, or even in Europe. The 

 British Lead Mining Company come next after Colonel Beaumont. 



* Pure galena is a compound of S59T4 lead and -1 sulphur. Hence eight cwt. 

 of galena contain 6"94 lead. But the galena employed in the smelting houses is 

 never perfectly pure, containing always antimony add iron, besides portions of 

 fluor spar and quarlz. This at least I found to be the case in ;ill the specimens I 

 examined. Hence the 21 per cent, of h.s-, which appears to take place in smelt- 

 ing :;.e ore, is probably chiefly owing to the presence of these foreign bodies. Yet 

 I think it probable that some improvements might be introduced into the mode of 

 roastii s the ore, where I suspect Uie greatest los.-. -if lead takes place. 



t I :,ave emitted introducing into this statement the Teesdale lead-mines, which 



are about 50 in number, because 1 !>ad no information respecting them. Should 

 they raise one-third of the ore furnKhid by the other parts of Durham and Norths 

 nmberland, which is not imp 

 v ould amount to 531,562 r w 

 quarter* of a million sterling. 



tliev raise oiie-tnira or mc ore rurniMira iiy rac omer parts oi l.u.in.im iiiiu noiin- 

 nraberland, which is not improbable, the whole lead fiiniL-hcd by this district 

 would amount to 531,562 rvrt. annually, the value of which would exceed Uiree 



