THE COAST or NORTHUMBERLAND. 257 
four miles west of Holy Isle. At the latter place, near the 
Abbey, the trap may be seen in some parts cutting through, 
in others resting on, or inclosing, the limestone and shale, 
which, when in contact with it, are much altered in their 
appearance. A coarse limestone appears to crop out from 
below the trap, near the Castle. 
The remainder of Holy Island consists of alternations of 
limestone, grit, coal, and shale. The seam of coal is seven- 
teen or eighteen inches thick, and was worked for a short 
time, but given up, on account of the quantity of water 
which oozed in from the sea : the pits were towards the 
north-west end of the Island. Small quantities of galena 
have also been found here. 
The Ferne Islands, or Staples, which at high water are 
between twenty and thirty in number, are many of them 
^5onnected at low-water (in which state they are represented 
In the plan) so as to form only about thirteen. They ap- 
pear to jcon^ist principally of a hard coarse trap, inclining 
to columnar, which in some of them rises to the height of 
nearly 100 feet above low- water mark. The steep sides 
generally face the south or south-west, and on the other 
side they slope gradually to a level with the sea. The same 
observation may also be made with regard to the basaltic 
eminences on the opposite coast^ and those more inland. 
At 74, is a mass of Jimestone four or five feet thick, sur- 
rounded with trap. 75^ a limestone, and compact felspar. 
At 77, large, loose, angular blocks of felspar passing into 
clay stone. 78, a bed of limestone, about five feet thick. 
In a vault of a tower, on the north end of the Ferne 
Island, is a well in the trap, now filled up with rubbish. 
Towards the north-west point a fissure proceeds some 
yards between two rocks, through which, in storms from 
that quarter, the sea is driven with great violence, and 
