152 
wards to the Tees ; for, although we have perhaps a less 
striking display of Millstone grit, no part of the superior or 
true coal measures is to be seen. 
The parish may be, perhaps, best described according to 
the variations of its interior strata under three heads, 
although two would suffice, for in a limited space of eighteen 
miles from East to West such oreneral o^eoloorical distinctions 
must necessarily be arbitrary, for one class of rocks will be 
found to extend partially into the second, and this graduate 
into the third. Nevertheless there is a sufficient difference 
observable to justify these divisions, and characterise the 
localities comprised in them. The botanist, from the pecu- 
liar aspect of the vegetation found in each, dependent on the 
fundamental differences of the interior structure, would pro- 
bably arrive at a similar topographical arrangement with 
respect to plants. 
With a view to illustrate my subject, I have endeavour- 
ed to construct a diagram, which is intended to represent a 
section of the strata, from the extremity of the township of 
Shelf on the East, to near Todmorden on the West. 
Here is Shelf, with an indication of its three workable coal 
seams, the one foot bed, the black bed coal, and the better 
bed.* This is an entire section of strata 120 yards from the 
surface, but it would occupy too much of your time to detail 
the particulars. At this point is the Back Clough Quarry, 
in Northowram, of handsome compact freestone ; and here 
we have the Shibden and Boothtown seams. At this point 
we come upon the Halifax gravel, beneath which there is a 
coarse gritstone, sometimes containing fossils, as in this 
instance found in digging the cellaring of the buildings now 
in progress at Northgate End. The Halifax and Elland 
coal seams are analogous in several particulars, presenting 
some agreements in thickness, succession, quality, and nature 
of the accompanying strata, afterwards to be noticed. The 
* See PI. III. 
