70 ' Dr Hibbert on the Dutrihutkm 
The direction of the mica- slate is very various, being from 
N. 25® E. to even N. 60“ E., increasing in this respect as we 
pursue an easterly course, calculated to cross the strata. The 
dip is to the west, generally at angles of about 45°. 
The Gneiss qfNecup^ Lunning-head^ Whalsey^ and the Out- 
sherries . — Tracing these strata in a general direction from 
S. W. to N. E. we find them, near the head of Catfirth Voe, 
taking their course as well from the main trunk of the lime- 
stone, as from that northerly ramification which passes through 
Vassa Voe ; consequently the circumstance of junction under 
which the gneiss is found, is similar to that of the mica-slate last 
described. Near this junction occur also small associated masses 
of granite, which seem to aid the limestone in affording at- 
tachments to the strata of gneiss. 
Certain of the strata seem to be continued uninterruptedly in 
a north-easterly direction, through Neap to Whalsey and the 
Outskerries ; whilst at Lax Voe a mass of sienite, about two 
miles in length, and half a mile in breadth, is opposed to the 
rest of the strata nearly at right angles. Their course being, 
however, resumed from other points of the sienite, the gneiss is 
variously continued to Lunning Head, to the islands between 
Lunning Head and Whalsey, to the western coasts of Whalsey 
and the Outskerries, and to Meikle Skerry. 
These strata are much traversed by veins of granite, and oc- 
casionally by sienite. At the Outskerries occurs a small round- 
ish mass of sienite on the Wart Hill, probably 300 feet in dia- 
meter, and a considerable bed of limestone, about 400 feet wide, 
the course of which is visible in a direction of N. 50° E. for a 
mile and a half. 
The strata, taking their course from the limestone, granite 
and sienite, to which they are attached, are severally directed 
to different points of the compass, viz. from N. 35° E., by which 
direction they are probably continuous with the distant island 
of Meikle Skerry, to N. 50® E., by which they meet the lime- 
stone or sienite of the Outskerries. The dip is to the west, at 
a variety of angles. The strata are, however, much confused 
by the occurrence of innumerable small insulated masses of gra- 
nite, seldom exceeding two or three feet in width. These sub- 
ordinate masses afford complete epitomes of the different cir- 
cumstances under which occur those mountain-masses of an in- 
