EFFECTS OF COAL ON HUMAN INDUSTRY. 397 



frontier of the enormous Coal basin of South Wales, in the 

 well-known Iron foundries, near Pontypool and Merthyr 

 Tydfil,* (See PI. 65, Fig. 2.) The beds of shale in the 

 lower region of this coal field are abundantly loaded with 

 nodules of argillaceous iron ore, and below these is a bed of 

 millstone grit capable of enduring the fire, and used in con- 

 structing the furnaces; still lower is the limestone necessary 

 to produce the fusion of the ore. PI. 65, Figs. 1, 2. 



The great iron foundries of Derbyshire, Yorkshire, and 

 the south of Scotland, afford other examples of the bene- 

 ficial results of a similar juxtaposition, of rich argillaceous 

 iron ore and coal. 



" The occurrence of this most useful of metals," says 

 Mr. Conybeare,t " in immediate connexion with the fuel 

 requisite for its reduction, and the limestone which facili- 



* In the Transactions of the Natural History Society of Northumberland, 

 Durham, and Newcastle, vol. i. p. 114, it is stated by Mr. Foster, that the 

 quantity of iron annually manufactured in Wales is about 270,000 tons, of 

 which about three-fourths are made into bars, and one-fourth sold as pigs 

 and castings. The quantity of coal required for its manufacture will be 

 about five tons and a half, for each ton of iron. The annual consumption 

 of coals by the iron works will therefore be about 1,500,000 tons. The 

 quantity used in the smelting of copper ore imported from Cornwall, in the 

 manufacture of tin plate, forging of iron for various purposes, and for domes- 

 tic uses, may be calculated at 350,000 tons, which makes altogether the 

 annual consumption of coal in Wales, 1,850,000 tons. The quantity of iron 

 manufactured in Great Britain in the year 1827 was 690,000 tons. The 

 production of this immense quantity was thus distributed. 



690,000 284 



+ Geology of England and Wales, p. 333. 

 VOL. I. — 34 



