113 



lower edge would cut obliquely across the bedding when seen 

 in vertical section, whereas the base of the purple-grey rocks is 

 parallel to the bedding, as shewn by me in Vol. 33, Part 4, of the 

 " Transactions of the North of England Institute of Mining and 

 Mechanical Engineers." 



If we look upon the purple-grey rocks as part of another 

 series resting unconformably upon the Lower Coal Measures, as 

 shewn by me first in Vol. 32, and again in Vol. 33 of the above-named 

 Transactions, one of the greatest difficulties we meet with in our 

 attempts at correlation is removed, and we can then understand — ■ 

 and we cannot otherwise — why seams that have been worked over 

 extensive areas should disappear all at once in the midst of coal 

 strata, and without any dislocation of that strata, or without any 

 previous thinning of the seam. On my explanation this is brought 

 about simply : the seams in the Lower Measures being cut off by 

 the overlying Whitehaven Sandstone series in a manner similar to 

 that which is known to occur in the Coalfield of Coalbrookdale. 



Under other circumstances I should have liked to reply to each 

 of Mr. Holmes' objections in the order in which they occur, but 

 want of space compels me to deal with his observations generally. 



Before concluding I would draw attention to what must be an 

 oversight in Mr. Holmes' paper. In his two diagrams of the 

 Coalfield he shews the Permians as if lying at a greater angle than 

 the Coal Measures. So far as my experience goes, the reverse is 

 the fact, so that the further we go to the dip the greater is the 

 number of seams we are likely to meet with in the Coal Measures. 

 I mention this simply because it has an important bearing on the 

 question under discussion by Mr. Holmes, and not by way of reply 

 to any of his criticisms. 



G. AND T. COWARD, PRINTERS, CARLISLE. 



