THE FRESH-WATER LOCHS OF SCOTLAND. 
253 
LOCHS OF THE NAN UAMH BASIN. 
The lochs to be dealt with here are Loch Dubh, between the head of 
Loch Ailort and the head of Loch nan Uamh, and Lochs Mama and 
na Creige Duibhe lying to the north-east. Loch Doir’ a’ Gherrain in 
Ardnish could not be sounded, because there was no boat on it at the 
time of the visit of the Lake Survey. 
Loch Duhlh (see Plate LVI.). — Loch Dubh is a small loch situated 
at the head of the peninsula of Ardnish, which separates Loch Ailort 
from Loch nan Uamh, the two branches of the sound of Arisaig. The 
Mallaig extension of the West Highland railway runs along its southern 
shore, and the outfall flows through the old bed of the little Lochan 
Deabhta, which has been completely drained by the railway, leaving 
only a channel through it for the escape of the waters from Loch Dubh. 
After leaving Lochan Deabhta the outfall joins the Schoolhouse burn, 
which has been deflected, thence into the Arnabol burn, falling into 
the head of Loch Beag, an inlet of Loch nan Uamh. It is surrounded, 
except on the western side, by low though steep hills, which impart 
a dark and sullen appearance to the loch, hence its name — the Black 
loch. Considering its superficial area, it is the deepest loch visited by 
the Lake Survey.* Its great depth, and the remarkable temperature 
conditions discovered in it, well repaid the trouble of carting a boat 
from Loch nan Uamh and carrying it down to the loch. Its catchment 
area is very small, and it would seem that the unpleasant taste of its 
water, resembling that of a stagnant pool, is due to the small amount 
of fresh water entering it. This unpleasantness is probably something 
more than mere taste, for attempts to stock the loch with trout have 
been unsuccessful, the fish rapidly dying ; eels, however, abound in it. 
Loch Dubh trends in a north-west and south-east direction, the 
broadest part being rather nearer the south-east end. Its length is 
* The deepest lake in East Prussia is, according to Halbfass [Globus, Bd. 86, p. 187, 
September 15, 1904), the Wuchsnigsee, which is about IJ miles in length, and has a 
maximum depth of about 210 feet. Loch Dubh is less than half a mile in length, and its 
maximum depth is 163 feet. 
