222 Murchisoris Silurian System. 



coal are, and how much they vary in different parts of the 

 same field ; the united thickness of the mass of coal in 

 any one shaft never being dependent on the number of 

 the seams. 



" A section of the Hill-Lane Pits, near Madeley, may be given as an 

 instructive example of the succession in one spot where the strata are 

 pretty fully developed. In a shaft two hundred and thirty yards in 

 depth, we are presented with twenty-one carbonaceous beds, of which 

 the eleven uppermost are sulphureous and impure. Upper coals, simi- 

 lar to those at Caughley and Tasley, alternate with clays, marls, sand- 

 stones both argillaceous and calcareous, and with calcareous breccia 

 or conglomerate. Some of these beds may represent the upper coal 

 measures of Manchester. The lower coals, or those extracted for use, 

 which in this shaft are reached at a depth of about one hundred and 

 ninety-eight yards, are named in descending order. 



Feet, inches. 



1. Viger coal, 18 



2. Two foot coal, 18 



3. Little Ganey, 7 



4. Lower Ganey, 16 



5. Best coal, 2 5 



6. Randle coal, 2 8 



7. Clod coal, 14 



8. Little flint coal, 2 6 



9. Coal under crawstone, 10 



10. Lancashire Ladies' coal, 9 



Total of good coal in this shaft, 15 11 

 " In the above list the beds which separate the seams of coal are 

 omitted. The following table will explain to the reader how little the 

 beds of coal are persistent, and how much they tary in their dimensions 

 in different parts of the field, the united thickness of the mass of coal in 

 any one shaft never being dependent upon the number of the seams. 



Pits. Thickness of coal. No of beds of coal. 



Yd. feet. inch. 



Hadley, ----- 15 ----- 16 



Sned's Hill, - - - - 14 2 2 12 



Malinslee, - - - - - 11 10 ----- 13 



Longley, ----- 11 2 6 ----- 11 



Dawley 14 ----- 16 



Lightmoor, - - - - 13 2 17 



Madeley, ----- 10 2 10 24 (21 to 24.) 



Braseley, ----- 709 13 



