1897.] NEW YORK ACADEMY OF SCIENCES. 225 



The large cotton and iron manufacturing towns of Lancashire 

 lie along the lower parts of the valley systems, the rest of the 

 country being occupied by grazing farms and quarries. 



On the south and west of the Lancashire coal field is the great 

 Cheshire and west Lancashire plain of Triassic rocks. The dis- 

 trict is almost entii'ely agricultural, flat and monotonous. 



Superficial Deposits. 



The subsoil of the coal field rests upon thick beds of clay en- 

 closing lenticles of sand and heavily charged with ice-scratched 

 boulders derived from country rocks and the volcanic series of 

 the north of England lake district. The glacial clays are of 

 considerable thickness in the valleys, thinning out upon the 

 flanks of some of the hills, but sweeping over some others under- 

 neath the peat. 



The solid geology is almost ever\'where obscured by these de- 

 posits except along the tracks of streams or where beds of grit 

 have withstood denudation and stand out as mural masses along 

 hill flanks. 



The mantle of stone-laden clay and sand is not so great a 

 hindrance to a study of the solid geolog}^ as one might expect, 

 since the heavy rainfall r44 inches per annum) and the rate of 

 fall of the hill slopes have caused each tiny stream to cut through 

 the clay and into the Coal Measures below, so much so that a 

 continuous section of a mile in length can be easily examined in 

 most stream courses. Streams are numerous and surface sec- 

 tions can be correlated with a fair amount of ease. 



Mining History. 



Whether coal mining was practised by the ancient Britons is 

 a point upon which there is no certain evidence. 



Previous to the time of the Roman occupation, Lancashire 

 was largely forest and swamps, and the ease with which wood 

 could be obtained discounts any theory of coal working by the 

 Britons. 



That coal was mined and used as fuel by the Romans is very 

 probable, for Whittaker, the Lancashire historian, has recorded 

 that the evidence of a large coal fire and an abundance of ashes 

 and scorioe were dug up in the " Castle Field " in the Roman 

 centre of Mancunium or Manchester.* 



Whether coal was used in Lancashire by the Saxons is not 

 known. 



That the coal was taken out at a remote period has been 



♦"History of Manchester," Vol. I., p. 301. 

 Transactions N. Y. Acad. Sci., Vol. XVI., Sig. 15, May 2d, 1397. 



