PARALLEL ROADS OF LOCHABER. 103 
On the other hand, it does not follow that the whole of the old Glen Spean 
Lake would be drained off at once. There is evidence, indeed, that immediately 
after the rupture of the Teandrish barrier three smaller lakes, at lower levels, 
were formed. One of these still subsists, now Loch Laggan, and of the other 
two there are well-marked vestiges. 
Loch Laggan forms a body of water, the level of which is about 40 feet 
below the original Glen Spean Lake, and now flows out, at its west end, instead 
of, as formerly, its east end. A trench through the detritus at its west end, of 
about 40 feet deep, allows its.surplus water to escape down the valley of the 
Spean by the river Spean. 
Formerly this river ran into a lake at a lower level, the western or lower 
end of which reached to near Inverlair. Its surface was about 640 feet above 
the sea. Its old beach-line is still visible, as is also the channel of the river 
by which its waters flowed down into the third lake. This third lake extended 
from Tulloch to near Monessie, a distance of about 3 miles, and stood ata 
level of 520 feet above the sea. Its beach-line, at that height, can be distinctly 
traced on both sides of the valley. 
This lake must have existed for a long period, or down to a comparatively 
recent date, judging from the breadth of its old beach-lines, 
I have in my previous Memoir explained, that this lower lake had been 
dammed by a blockage of detritus at its west end, and which had been cut 
through at one side, leaving the rest of the blockage still standing. (Page 609.) 
The narrow passage in the rocks through which the river now rushes at 
Monessie, seems to have been an original fissure in the rocks, which probably 
had been at a former period so filled and choked with detritus, that the waters 
of the lake did not reach it. 
Before this lower lake was drained off, the water from it would flow over 
the ridge which crosses the valley at Monessie, and form a stream reaching the 
sea somewhere near the Roman Catholic Chapel. 
An old river course is visible, to the north of the present river channel, 
between the river and the turnpike road, at a height of about 420 feet above 
the sea, or about 80 feet above the present channel of the river at this place. 
It seems not improbable that whilst this lower lake existed,—the sea 
reached up to near Monessie, in which case the fall from the lake to the sea 
may not have been more than 50 or 60 feet.* 4 
*It is a curious circumstance that the old Celtic names of several places in Glen Spean are in 
accordance with the conclusions of geological observation and reasoning. The Ordnance Map marks a 
spot at Inverlair as Ceann-a-Mhuir, which means the head of the sea, or lake. At Inverlair there is 
now neither lake nor sea. Was there, a lake, reaching up to Inverlair, when this name was given? 
The Map likewise marks a spot lower down Glen Spean Valley as Ceann-na-Mara, which has 
exactly the same meaning as the above, though varying in form, in the same way as ‘“ Loch-end” and 
«End of the Loch,” Can this refer to the west end of the supposed loch, or can it refer to the sea, 
