the Parallel Roads of Glen Roy. 27 
standing at their respective levels. The ‘‘roads” above and 
below where you happen to be standing of course appear curved 
by perspective, and can be seen winding round the hill-sides. 
It has been proved that each ‘‘road”’ is accurately horizontal ; 
so much so that the road in the far distance distinctly dips 
below the horizontal level, just as a water surface does, owing 
to the earth’s curvature. It is probably because the eye in- 
stinctively recognizes this curvature that the impression of a 
lake-shore is so irresistible. 
GLEN GLAS DHOIRE 
LOOKING EAST. 
Beam x Mheiehliak Creny Bhatt 
s te 
Fic. 4.—A sketch view from Bohuntine Hill, at the level of the middle 
“road,” showing how the different ‘‘roads’’ variously end upon the other 
side of the glen. 
That was looking north. Now, from near the same spot take 
another view, looking east, of the ‘‘roads’’ on the other side of the 
glen. Here you see a branch valley—Glen Glas Dhoire—cutting 
off a big hill—Creag Dhubh—-from the eastern mountain wall of 
the Glen Roy Valley; and looking up that Glen Glas Dhoire 
Valley, you see it ends in a broad flat “col” (mountain pass or 
_valley watershed). Now note how accurately that ‘‘col’’ corre- 
sponds with the level of the middle ‘‘road.’’ The impression of 
a lake overflowing there is insistent, almost irresistible. (In 
