434 D. MACKINTOSH ON THE ERRATIC BLOCKS OF 
bed of the Irish Sea to the peninsula of Wirral and the south-west 
corner of Lancashire around Liverpool. In the higher part of 
Liverpool Criffel granite greatly preponderates over Eskdale, and in 
the back streets there are many large boulders of this granite, which 
we have no reason to suppose were brought from any considerable 
distance. Jn the excavations for the New North Docks numerous 
large boulders of Scottish “‘ greenstone” were found. But it is chiefly 
in the peninsula of Wirral, between the estuaries of the Dee and 
Mersey, that Criffel-granite boulders are found; and there they are 
associated, not only with ‘‘ greenstone,” but with numerous large 
boulders of felstone, felspathic porphyry, and strongly marked fel- 
spathic breccia (from the Lake-district), which, for reasons already 
stated (see I. § 7), must have been transported at a separate period. 
They may be seen in every village in the peninsula; but they occur 
so plentifully between West Kirby and Parkgate as to suggest the 
idea of an intermediate concentration. They may be best studied on 
the sea-coast at Dawpool, between the two spots marked “ Lime- 
kiln” on the one-inch Ordnance Map. ‘There they have been prin- 
cipally washed out of the lower part* of the Lower Boulder-clay, 
which upward becomes less stony, until it is surmounted by a nearly 
stoneless sand, which is capped with Upper Boulder-clay. The clay 
cliffs present a variety of details which are calculated to bewilder 
the observer who has not frequently studied them as fresh faces 
are exposed by the constantly encroaching waves. Both upper and 
lower clays are undoubtedly stratified ; and though the erratic stones 
(which in the lower clay are generally angular or subangular, and 
in the upper clay more or less rounded) occur in all positions in the 
clay, relatively to their longer axis, they are sometimes grouped in 
the same divisional plane, with their upper surfaces striated in the 
same direction, in this respect somewhat resembling Hugh Miller’s 
‘striated pavements.” Further south there are many Criffel boulders, 
especially about Neston, and they may be seen predominating over 
Eskdale all the way to Chester. The large boulders which may be 
seen in the poorer quarters of Chester (where they answer the pur- 
pose of seats for aged women on summer eyenings) have been col- 
lected from excavations made for house-sites &c., or brought from 
the neighbourhood, ever since the time of the Romans. Many of 
the smaller stones with which the courts and some of the streets are 
paved are said to have been brought by water from the shores of 
the estuary of the Dee. Among the stones, as usual, Silurian grit 
predominates. I once made a survey of all the large boulders I 
could find, which resulted in 41 Lake-district felstones, more or less 
porphyritic and brecciated ; Criffel granite 15 ; Scottish “ greenstone” 
9; Eskdale granite 9; Lake-district syenite 2; Carboniferous lime- 
* This lower part is a stratified loam (often quaquaversally arranged) in 
which the boulders and smaller stones are very unequally scattered, many parts 
of it being almost stoneless. At Dawpool it is the ouly representative of the 
Lower Boulder-clay which is exposed on the sea-coast near Bootle, Cumberland, 
at Blackpool, and in Colwyn Bay, North Wales, where it is underlain bya blue 
clay almost entirely destitute of erratics, though full of local stones. 
