the Parallel Roads of Glen Roy. 29 
world like a huge railway embankment, with a level top as high 
as the roof of a house which is built under its lee. This really 
-ig the side view of a huge terrace or platform half a mile across, 
with its upper surface a few feet below this same (850 ft.) level. 
In one place sand is being dug from it. Proceeding eastward, 
while passing Loch Laggan, the coach-road is generally on a 
terrace at this same 850 ft. level; and at the head of the valley 
the ‘*col’’ at Makoul is at the same height (850 ft.) as this 
lowermost parallel ‘‘road,’’ which we have traced all the way from 
Glen Roy up the Spean Valley; so you see the level of each 
‘“‘road”’ corresponds to that of a ‘‘col’’ into which it runs. 
Now what was the cause of these parallel “‘roads’”»? How came 
they there? That is the question which makes them so in- 
teresting. Are they raised sea-beaches? Well, consider that 
there are hundreds of similar glens all round about. Remember 
how distinctly the ‘“‘ roads”’ are marked in Glen Roy, and that 
no trace of them appears anywhere else. 
There is, however, just one other parallel road, and this is 
found in the next-door valley, Glen Gloy; and there, though 
this fourth ‘‘road’’ occurs on the other side of the same 
mountains, though it approaches within a few hundred yards of 
our highest Glen Roy “road,” yet it is at a level which is dis- 
tinctly higher than this ‘‘ road,”’ but corresponds instead to the 
level of the ‘‘col”’ at the head of its own valley. Could the sea, 
have made this fourth parallel ‘‘road”’ in Glen Gloy, and yet make 
no trace of a parallel ‘‘road”’ at this level in Glen Roy? Or can 
you believe that the sea was standing for a long time at the lower 
levels of the Glen Roy “‘roads,’’ and made no corresponding marks 
in Glen Gloy? Or, more incredible still, can you believe that 
the sea could have stood at these four different levels, and yet 
left no other traces in the hundreds of similar valleys all over the 
country? No alteration of sea-level can explain why parallel 
‘roads ’’ were formed just here and nowhere else. 
Then again, since in every instance the “‘road’’ corresponds 
to the level of its particular ‘‘col,’”’ the conclusion is natural 
that that ‘* col” was concerned in the formation of that ‘ road.” 
Why should the ocean choose to stand still always just at the 
level of a “col”? No! ‘These ‘roads’ are distinctly local 
and peculiar, and require an explanation that is also local and 
peculiar ; and this is ready to hand. If the lower half of Glen 
Roy were to be blocked up, obviously the rain and water would 
accumulate in the upper part until it gently overflowed at the 
lowest available level; this is the ‘“‘col”’ at the top of the glen 
communicating with Strath Spey, and the water would remain 
at that level as a lake, which would wash a shore or beach out 
of the soft steep bank round its edge. Thus the highest parallel 
“road” is made. Now let the obstruction which we suppose blocked 
