Amo7tg the Ancie7it Glaciers of North Wales. 11 
most incurious person can hardly fail to be struck with the great 
■difference between the character of this rock and the clay slate upon 
which it rests. If the observer casts his eye around him, he will be 
unable to see in any direction traces of a similar geological forma- 
tion in the neighboring rocks. A few feet further on, however, he 
will observe a third angular block of stone, larger than the others, 
but resting, like them, upon two or three points alone. He can 
hardly fail to be struck with the fact that these three blocks are in 
as exact and regular a line as if their places had been laid down by 
the nicest measurement. They run nearly northwest and southeast 
—about half a point to the west of N W. and to the east of S. E.— 
that being the general direction of the ridge which descends from 
tlie spur of Glyder Fawr. 
If we now remount to the top of the knoll, we shall perceive that 
the side of the steep inclines towards the hollow referred to before, 
is dotted here and there with large blocks of stone resting gently 
upon the sloping rock, or imbedded in the turf. All these, on ex- 
amination, will turn out to possess the same sharp and angular 
character ; and all of these suggest the question : Is it possible 
they could have rolled so far up hill ; and were it possible, could 
they be as sharp and unrounded as they are? Still, however, we 
see no sign of the red conglomerate. As we pursue our way north- 
west towards the spur of the Glyder, we find the ridge growing 
rapidly steeper, but still we see this regular line of sharp blocks, 
deposited often on their sharpest edges, and nearly on the edge or 
backbone of the rock. As we mount, they become larger and 
more frequent, and amongst the higher rocks are one or two small 
. fragments of red conglomerate— until at length, just behind a huge 
mass of clay-slate of a size which would do credit to any moraine in 
Switzerland, we come suddenly upon a block of conglomerate 
fifteen feet long and ten feet high, large enough and sufficiently 
overhanging to afford us no mean shelter from a Welsh mountain 
storm. Five minutes' further climbing in the same direction brings 
us to a most gratifying sight— a large patch, seventy or eighty yards 
wide, of the red conglomerate in situ — of exactly the same character 
in every respect as that which we first observed resting on the side 
of the clay-slate knoll some two miles away. Looking back we 
shall be able to trace distinctly the line of stones by which we have 
been guided in our ascent. It is so regular that they might 
almost have been dropped one after the other by a railway train. 
On each side of the principal line of stones we may observe other 
