EXPLANATION OF PLATE 67. 105 



resulting from these Interruptions of the continuity 

 of the strata are pointed out in pp. 406, 407. 



A large portion of the surface of these strata near 

 Newcastle is covered with a thick bed of diluvial 

 Clay interspersed with Pebbles, in the manner re- 

 presented at the top of this Section. The effect of 

 this Clay must be to exclude much rain-water that 

 would have percolated downwards into the Coal 

 mines, had strata of porous Sandstone formed the 

 actual surface. 



Plate 67. V. I. p. 417. 



Fig 1. represents the case of a valley of Denudation in 



Viewer has presented to the Natural History Society of Newcastle, 

 copies of his most important plans and sections, accompanied by written 

 documents, of the under ground workings in the Collieries near that 

 town, in which all those spaces are carefully noted, from whence the 

 Coal has been extracted. Every practical Miner is too well acquainted 

 with the danger of approaching ancient workings in consequence of the 

 accumulation of water in those parts from which Coal has been re- 

 moved. The sudden irruption of this water into a mine adjacent to 

 such reservoirs is occasionally attended with most calamitous and fatal 

 results. See History of Fossil Fuel, the Collieries and Coal Trade, 

 1835. P. 249 et seq. 



The distates of humanity which prompt us to aid in the preserva- 

 tion of human life, no less than the economical view of rendering avail- 

 able at a future time the residuary portions of our beds of Coal, which 

 will not now repay the cost of extracting them, should induce all pro- 

 prietors and other persons connected with Coal Mines, and especially 

 Engineers and Coal Viewers, to leave to their successors a legacy, 

 which will to them be precious, by preserving minute and exact records 

 of the state of the coal in their respective districts: It can, however, 

 scarcely be expected, that such measures will be generally and syste- 

 matically adopted throughout the many Coal fields of this country, 

 unless the subject be legislatively taken up by those official persons, 

 whom it behoves, as guardians of the future welfare of the nation, to 

 institute due measures, whilst the opportunities exist, for preventing 

 that loss of life and property, which a little attention bestowed in sea- 

 son, will preserve to posterity. 



