8 description of the rocks 
(81° and 99° measured on a horizontal plane.) (4) Other vertical joints 
of less continuity also pass through the tables. (5) Oblique joints are 
frequent. (6) There are also horizontal and undulating and slightly 
inclined joints or floors, which are of short and uncertain extent, 
affecting some tables and not others. (7) There is yet another set of 
planes In this singular slate called ‘rows,’ which generally present a 
few parallel edges on the tables, and pass with different degrees of 
inclination to the horizon through their substance. In the quarry from 
which the preceding details are drawn, they dip N. N. W., and cross 
all the other planes, sometimes appearing to effect a small displacement, 
so that they are a kind of faults. 
For the sake of distinctness the above description has been taken 
from one quarry. The most constant circumstances of structure are 
three. The strike of the ‘ spires’ is E. S. E. ; that of the ‘ bate is about 
E. ; and that of the ‘ ends’ nearly N. The same ‘ strike of the spires’ is 
noticed in most of the quarries under Houghton Scar, but the dip 
there is 70°, 45°, and 80°, S. W. by S. The same direction is also seen 
on the east of the Ribble, with a dip of 45° S. S. W., and at a point 
further north, with a dip 15° to N. N. E. ; the same direction of the 
cleavage planes has been noticed in Leclc Beck, Ingleton, Clapham, and 
the valley of Wharfe, and always with a dip to the S. S. W. 
Is this rock stratified? what are the planes of stratification? To 
these questions in 1827, after exceeding labour and reflection, I did 
not venture to offer a reply ; and though since that time I have 
repeatedly examined this district, with the advantage of knowing Pro- 
fessor Sedgwick’s sentiments, it is with some hesitation that 1 adopt an 
opinion. Taking the clearest case first, there appears sufficient evidence 
in the quarries and other exposures in Ribblesdale, (Come Wood, under 
Moughton Scar, and Flat Rocks,) to establish for that part of the slaty 
range, the conclusion, that the * spires’ are planes of stratification, and 
the tables, or flags, true laminae of deposition. The following is t le 
evidence : — 1. Alternations of soft substances between the flags. 2. Pa- 
rallel layers of pyritous ‘ galliard’ rock. 3 . Small septana and hard 
