440 D. MACKINTOSH ON THE ERRATIC BLOCKS OF 
granite and Lake-district felstone accompany Criffel granite along 
the north coast of Wales, from Flint to Anglesey. ‘They are most 
numerous on Halkin Mountain, near Rhos (Colwyn Bay), Llanfair- 
fechan, Bangor, and Beaumaris. They have found their way into 
the interior as far, at least, as the neighbourhood of Cefn Cave (near 
St. Asaph) and Moel-y-Tryfaen. 
3. North-east and east fowndary Oe ESD Se a ee of 
Blackpool Boulder. South 
of the initial concentration, near Silecroft, the east boundary of the 
granite suddenly bends round and runs up Whicham valley for some 
distance, as if the boulder-laden ice had been blown aside by wind. 
After crossing the south-west end of Millom hill, it runs north-east 
up the Duddon valley, crosses the estuary, and then runs south-east 
by Great Urswick to the sea. It reappears on the east coast of the 
Irish Sea some distance north of Blackpool. On Blackpool beach 
many boulders have becn washed out of the Lower Boulder-clay. 
Eskdale granite predominates over Criffel, and is accompanied by 
large boulders of Lake-district felstone and “Mountain Limestone, the 
latter from the neighbourhood of Carnforth, Burton in Kendal, &c.* 
From the north of Blackpool the boundary runs by Longridge to 
Rochdale, over the western spurs of the Pennine hills, on which 
Mr. Aitken, F.G.8., has found boulders of pink (Eskdale) granite at 
a height of 1100 feet, and felstone and syenite at greater heights. 
From Rochdale it runs south-east to Swineshaw valley (near Staley- 
bridge), where it turns off at right angles to its general course, 
and goes up the valley to an altitude of at least 900 feet. From 
Swineshaw valley it runs south into the heart of the western division 
of the Pennine hills. The furthest east boulder I could find was 
close to Macclesfield-Forest smithy, which is about five miles east of 
Macclesfield town. It was a Lake-district felstone about 3 feet in 
length, and probably about 1300 feet above the sea. Further west, 
on the south side of the Macclesfield road, I found a similar felstone 
boulder about 33 x 22x14 foot. Many large felstone and Eskdale 
boulders may be seen along or near to the road around the ‘ Setter 
Dog’ inn, and between it and Macclesfield. The highest Eskdale- 
granite boulder I could find was a short distance cast of the ‘ Setter 
Dog,’ at a height of about 1200 feet above the sea, or very nearly as 
high as its greatest height in the Lake-district. Among the larger 
granite boulders Eskdale predominates, among the smaller Criffel. 
Besides the felstones (which are often porphyritic) and granites, 
syenite and a kind of rock apparently about midway between 
syenite and greenstone may often be secn in the neighbourhood of 
Macclesfield. South of Macclesfield Forest the boundary of the 
Eskdale granite and Lake-district felstone runs at least as far east 
as Harecastle (where I saw a very large Eskdale-granite boulder 
immediately behind the police-station); Etruria, west of which, in 
* They may be traced on their way §.8.W. at Morecambe, near Lancaster. 
+ Mr. Sainter, F.G.S., in his ‘Rambles round Macclesfield,’ mentions a 
boulder of por phyritic felstone, now in Macclesfield Park, which is about 6 feet 
in average diameter. 
