398 
BATHYMETRICAL SURVEY OF 
volume of water is 123 millions of cubic feet. The drainage is chiefly 
brought by the river Loyne, only small burns contributing a share, the 
largest entering close to the outflow. 
The prominent points on both shores, and the large island, are 
formed by mounds of boulders and gravel. The only rock seen was 
at the very narrow channel, with a depth of only 2 feet, at the east end 
of the largest basin. Here rock was exposed on both sides. The river 
flows out between an alluvial flat on the north and mounds of glacial 
debris on the south. The height above the sea was 706T feet on 
November 4, 1904. 
The temperature of the surface was 46°*6 Fahr., and at 30 feet 46°’2. 
Loch ail Staca (see Plate Cl.). — Loch an Staca is a considerable 
minor loch, of roughly triangular form, situated on the extensive 
elevated area which stretches westward from Loch Ness, between Glens 
Moriston and Urquhart. It is 6 miles distant from Loch Ness. Its 
longer axis lies nearly north-east and south-west. The undulating 
moorland rises little above the loch, except on the east, where Meall 
na Criche, 2224 feet in height, sends a long ridge southward between 
Lochs an Staca and na Criche. 
Loch an Staca is estimated to be 1600 feet above the sea. It is 
a mile long by two-fifths of a mile broad, with a mean breadth of a 
quarter of a mile. The superficial area of the loch is about 163 acres, 
or a quarter of a square mile, and the drainage area square miles. 
The volume of water is 110 millions of cubic feet. 
Loch an Staca receives only local surface drainage, and the overflow 
is carried into Loch Liath by a small burn. The bottom is very uneven, 
a depth of only 9 feet being found almost in the centre of the loch, 
with deeper water on all sides. There is a small island close to the 
west shore. A great part of the bottom, equal to 74 per cent, of 
the total area, is covered by less than 20 feet of water. Four little 
depressions occur. The deepest, with the maximum depth of 51 feet, 
is close to the east shore ; another of 32 feet lies to the south-west 
of this ; one of 30 feet close to the west shore north of the island ; and 
one of 30 feet in the centre of the loch, near the north end. At this 
end is another island. The mean depth is 15 J feet. 
The surface temperature (June 2, 1904) was 56°‘5 Fahr. ; at a depth 
of 25 feet it was 52°-0, at 50 feet 48°-9, a total range of 7°’6. 
Tjoch Liath (see Plate Cl.). — A little roundish loch about a mile 
to the south of Loch an Staca, on the same plateau. It is about 100 feet 
lower than Loch an Staca, the drainage from which it receives. The 
axis of the loch has a north-east and south-west direction. It is barely 
half a mile long by fully a quarter of a mile broad, with a mean breadth 
of one-fifth of a mile. The superficial area is about 61 acres, and its 
