XORTU-WEST OP EXGLAXD AXD XOETH WALES. 85 



occurrence is what ' nay previous investigations would have led me 

 to expect. 



A boring for water at Burscough-Bridge Station shows the rock 

 to "be there 22$ feet below ordnance datum, and to have 278 feet of 

 drift, mostly sand and gravel, with some Boulder-clay beds, lying 

 upon it. Thus there is progressive declination in the rock-level 

 from Warrington towards the mouth of the Eibble. 



Drift in the neighbourhood of Liverpool and on the Lancashire 

 side of the River Mersey. 



The Boulder-clay in the neighbourhood of Liverpool, though largely 

 used for brick-making, is not a brick-clay in the same sense as the 

 Clyde laminated clays. It contains many stones and in some places a 

 good deal of limestone, which is apt to burst the brick when exposed 

 to the weather after being calcined by the burning. In some cases 

 the clay is passed through a machine to crush the stones. In places 

 there are considerable depths of a fine unctuous clay, which has 

 hitherto been considered unfit for brick-making ; but the New Perry 

 Brick and Tile Company have proved this to be an old-fashioned 

 delusion, as they produce much more perfect bricks than the ordinary 

 Lancashire or Cheshire make, and even tiles, with a very fine clay 

 belonging to this series. 



I have touched upon the economical aspect of the question, as it 

 enables a stranger much better to realize the geological nature of 

 the clays. 



In this clay and underlying it, as I shall presently describe, are 

 beds of sand and gravel. 



They rarely show at the surface in the district delineated ; but 

 sand beds are common in some other areas, and replace the Boulder- 

 clay as a surface-deposit. 



In my descriptions I do not propose to use the terms "Upper" 

 and " Lower" Boulder-clay and " Middle Sands and Gravels" as I 

 consider these titles beg the question which it is my purpose to 

 discuss. 



Sections exposed in the North Docks at Bootle (fig. 1). — Excava- 

 tions for the Huskisson Branch Dock in 1872 showed the old 

 shore-line of the river, consisting of silty gravels (with recent 

 shells) from 1 ft. Gin. to 2 feet thick, buried below the spoil filled in 

 to form what was the Dock quay. The shore-line had been cut in 

 the Boulder-clay, which was 24 feet thick at the deepest part, and 

 consisted of an extremely homogeneous plastic clay containing 

 occasional rounded pebbles and a few of the usual erratics. Beneath 

 the clay was a bed of gravel from 2 ft. 6 in. to 3 ft. 6 in. thick, resting 

 on red sand which covered the rock. 



The rock-surface would therefore be about from 12 to 14 feet below 

 ordnance datum. 



A few irregular patches of sand occurred in the clay ; but they 

 were devoid of form or stratification. 



In June 1874 I examined the excavations for the new Alexandra 



h2 



