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their existence to them. About 4,000,000 tons are annually 

 raised, and owing to the want of a cheap and quick com- 

 munication to the sea, on the one hand, only comparatively 

 few tons are annually exported, while Northumberland and 

 Durham export 7,000,000 tons; and, on the other, without 

 any connection with any main trunk lines of railway of the 

 country, as the Sheffield and Manchester, or Midland, the 

 Coal-field from Wakefield to near Sheffield is completely cut 

 off from all cheap and quick modes of transit. Some of the 

 lower portions of the strata of this Coal-field are prolonged 

 into Derbyshire, and others into Lancashire. The vertical 

 thickness of the whole strata is about 1,200 yards, which 

 may be divided into three parts. The lowest portion, about 

 200 yards thick, does not produce coal of any very great 

 value. The middle portion, prolonged into Derbyshire, is 

 about 600 yards thick, and contains the most productive and 

 richest number of coal seams. The upper portion, about 

 300 yards thick, consists entirely of coarser arenaceous beds, 

 and the coal beds do not, as lower in the series, cover large 

 areas. 



The Rev. Gentleman proceeded into a minute detail of the 

 various seams of coal, their position, quantity, and quality, 

 which he illustrated by reference to various sections, and 

 mentioned the fact that, in the lowest portion, although the 

 Coal was of inferior quality, yet there was no portion of the 

 Coal-field more curious in its Geological relations, and par- 

 ticularly with regard to a considerable diversity of marine 

 shells, which are found in several parts of the Coal-field near 

 Sheffield, Halifax, &c. 



The average vertical thickness of solid coal in Yorkshire is 

 from 90 to 100 feet, and Humboldt asserts that in the tem- 

 perate zone the growth for 100 years of the forests upon any 

 given part would not cover it seven lines (not half an inch) in 

 thickness with carbon ; and therefore in order to account for 



