249 
the south, at a depth of sixty-eight fathoms from my Belgium 
pit, to cut the upper section of seams that lie over the ordinary 
Kingswood series and between those and the Pennant rock; 
at the same time I started a drift to the north, at a depth 
of 500 yards from the bottom of Speedwell pit; and it is the 
discovery made by the latter, or north drift, from Speedwell, 
that I now venture to lay before you. 
For some 200 yards this drift was driven in strata nearly 
upright, and exhibited traces of great disturbance and enor- 
mous lateral pressure, and in fact the whole of the Kingswood 
district has in past workings exhibited proofs of enormous 
disturbance and displacement, chiefly, as I some time ago 
explained in a paper which I published, having been produced 
by lateral pressure, and not by vertical movement. 
I should explain that my object in driving this under- 
ground tunnel was to strike, as I expected, the lower or Ashton 
series of veins—in other words, the lowest section of seams in 
_ the Coal-field. With the assistance of a Section which two of 
the students of our Bristol Mining School have prepared, [| 
_ shall be able to show you the steps by which I have reached 
the discovery we have lately made. Some 250 yards north of 
Speedwell pit we cut a seam of Coal about two feet four inches 
thick, in an upright position, and for a long time I sup- 
posed this to be the first of the lower, or Ashton, series of 
_ veins. 
But extending the drift some 50 to 100 yards farther to the 
‘north we found the strata became horizontal, and we struck a 
second seam of Coal, in several separate beds, the thickest of 
which was about twenty inches thick. For some time I sup- 
posed this vein to be a second vein in the lower or Ashton series ; 
but after following the vein for some 50 to 100 yards I found 
that it was one of our old Great Vein group that had been 
worked 300 to 350 yards overhead up to the eater of the 
vein, near the surface. 
I hesitated for a long time to accept the conclusions to 
which this fact pointed, it was so difficult to explain or account 
for, that I resolved before coming to any decided conclusion 
T 2 
