1897.] NEW YORK ACADEMY OF SCIENCES. 233 



to represent the Bradford four feet. If this be the case it marks 

 the upper limit of the Middle Coal Measures. 



Nowhere in this area is the whole of the Middle series pres- 

 ent from summit to base, unless it be to the south of Dunkinfield 

 a,nd at Moston. 



(b) Bolton and Bury Area. 



In this area the Middle Coal Measures reach full}' a thousand 

 jards in thickness and scarcely any portion remains untouched, 

 mining being particularly active. 



The best generalized section of it is that of Professor Hull, 

 curtailed from a much more detailed section published by J. 

 Dickenson, Esq., late Her Majesty's Inspector of Mines. 



Generalized Section Between Manchester and Bolton. 



Ft. In. 



Worsley Four Feet Coal 4 3 



Strata 782 



Bin Coal 3 6 



Strata 78 



Albert Mine 3 3 



Strata 42 



•Crumhourke Coal 4 



Strata 144 5 



Rams 3Iine 5 6 



Strata 254 7 



White Coal 3 



Strata 21 



Black Coal 3 



Strata 45 



Old Doe Coal 8 



Strata 31 



Five Quarters Coal 3 6 



Strata 266 



Irenchhone Coal 5 



Strata 102 



Cannel 31ine (Cannel only 6 in. ) 4 6 



Strata 58 



Saplin Coal 4 



Strata 107 



Plodder Coal 3 



Strata 114 



Yard 3Iine 3 



Strata 168 



Three Quarters Mine 2 



Strata 206 



Arley 3Tine 4 



(Slightly modified from Hull's Coalfields of Great Britain 1881, pp. 

 202, 203.) 



