168 
BATHYMETRICAL SURVEY OF 
LOCHS OF THE POLLY BASIN. 
Only the two principal lochs in this basin (Lochan Gainmheich and 
Loch Skinaskink) were surveyed ; Loch na Doire Seirbhe, Loch Lon 
na-h-Uamha, Loch Uidh Tarruingeach, and other smaller lochs had no 
boats on them at the time of the visit of the Lake Survey, and it was 
found impracticable to have boats transported to them. The waters of 
Lochan Gainmheich are discharged into Loch Skinaskink, thence by 
the river Polly into Loch Polly, an inlet of Enard Bay. 
Lochafi Gainmheich (see Plate XXXIX.). — Lochan Gainmheich lies 
about 1-1 miles to the north of Loch Lurgain and a quarter of a mile to 
the south-west of Loch Skinaskink, into which its waters are discharged 
by the Allt Lochan Gainmheich. The eastern end of the loch lies 
between Cul Mor and Cul Beag, and to the west An Stac rises to over 
2000 feet; Cul Beag and An Stac are connected by a ridge between 
Loch Lurgain and Lochan Gainmheich over 200 feet above the level of 
the loch, so that only towards Loch Skinaskink can an extensive view 
be obtained. The southern shore of Lochan Gainmheich is thickly 
wooded, but the northern and western shores are bare. The loch is 
naturally divided into a larger and deeper southern portion and a 
smaller and shallower northern portion, and it has been found con- 
venient to measure these two distinct portions separately. 
The southern portion is a mile in length from east to west, and 
nearly half a mile in maximum breadth, the mean breadth being over 
one-fifth of a mile. The area is about 135 acres, and it drains an area 
of nearly 2| square miles. Over 50 soundings were taken, and the 
maximum depth observed was 120 feet. The volume of water is 
estimated at 245,711,000 cubic feet, and the mean depth at nearly 42 
feet. This portion of Lochan Gainmheich is extremely simple in 
conformation, the bottom sinking down on all sides towards the deepest 
part, which is approximately centrally placed. The 50-feet area is 
about 1100 yards in length, and the 100-feet area about 400 yards in 
length, the maximum depth of 120 feet having been observed about 
130 yards from the southern shore. The areas between the contour- 
lines, and the percentages to the total area, are as follows : — 
