158 MESSRS. KIRKBY AND DUFF ON THE 



Feet. In. 



COAL 9 



Grey shale 37 7 



Blackshale 7 



Ft. In. 



Coal 1 4 



FIVE QUARTER COAL ■ Band 1 6 



.Coal 2 2 



Fireclay..... 8 



White sandstone 33 



COAL 10 



Grey sandstone girdles 11 



Grey "whin" 4 



Blue shale 6 



COAL 8 



Fireclay 4 2 



Blue shale 6 4 



COAL 1 3 



Grey shale, with sandstone girdles 15 



White sandstone s 19 1 



Blueshale 3 



BROCKWELL COAL 4 



208 



It will be observed tbat botb tbe Five Quarter and Broekwell 

 coals diminisb in thickness towards the south-west. The former, 

 from a six feet seam, thins out to about three inches ; the latter, 

 from nearly seven feet (inclusive of cannel), to four feet. The 

 decrease is partly due to the coming in and gradual thickening 

 of bands of fireclay or shale in the seam, so as ultimately to 

 separate it into distinct portions, one usually being thin and 

 unworkable. Another mode of sectional decrement is by the 

 upper or lower layer of the seam becoming coarse and banded 

 with earthy matter, and thus of no value as coal. On the fol- 

 lowing page we give, from actual measurement, the thickness of 

 these seams in six localities, commencing with the most south- 

 westerly we have been able to inspect. Further to the nortb, 

 in the valley of the Tyne, coals equivalent in position are wrought 

 under, we believe, the same names : in the east of the coal-field 

 their horizon does not appear to have been reached. 



