154 
BATHYMETKICAL SURVEY OF 
preserved ; they contain trout, with pike in Lochs Alvie and Gaol na Loire, 
salmon in Loch an t-Seilich, and char in Loch Builg. 
Loch Crunachan (see Plate LVI.) lies about 7 miles to the north-west 
of Lalwhinnie on the Highland railway, and 11 miles to the south-west 
of Newtonmore, Loch Laggan hotel, at the head of Loch Laggan, being 
less than 2 miles to the south; The loch trends in a north-east and south- 
west direction, and is two-thirds of a mile in length, with a maximum 
breadth of a quarter of a mile, covering an area of about 68 acres, and 
draining an area of nearly 4 square miles. The maximum depth of 25 feet 
was observed towards the south-west end of the loch. The volume of 
water is estimated at 23 million cubic feet, and the mean depth at nearly 
8 feet. The loch was surveyed on June 5, 1902, but the elevation could 
not be determined; on December 18, 1872, the officers of the Ordnance 
Survey found it to be 878*9 feet above the sea. The loch forms a simple 
shallow basin, a considerable area at the northern end being under a foot 
in depth, and about 78 per cent, of the lake-floor is covered by less than 
10 feet of water. Weeds are abundant, especially at the north-eastern 
angle, where the burn flows out. 
Temperature Observations . — Temperatures taken in the deepest part of 
the loch gave the following results : — 
Surface ... 
5 feet . . . 
10 „ ... 
20 „ ... 
56°*0 Fahr. 
54°*0 „ 
48°*2 „ 
47°*5 „ 
These observations show a range of 8°*5 from surface to bottom, the 
greatest fall being one of 5°*8 between 5 and 10 feet— a fall exceeding 
1° per foot of depth. 
Loch Gaol na Loire (see Plate LVI.). — Loch Gaol na Loire (or Goul- 
tree) lies about 3 miles from Lalwhinnie, and about 5 miles to the east 
of the head of Loch Laggan. In outline it is pear-shaped, trending nearly 
east and west, and nearly three-quarters of a mile in length, with a 
maximum breadth across the wide western portion of nearly one-third of 
a mile. The superficial area is about 77 acres, and the drainage area 
nearly Ij square miles. The maximum depth of 55 feet was observed 
approximately in the centre of the wide western portion of the loch. 
The volume of water is estimated at 77 million cubic feet, and the mean 
depth at 23 feet. The loch was surveyed on May 14, 1904, but the 
elevation could not be determined ; on December 2, 1872, the Ordnance 
Survey officers found it to be 1140*7 feet above the sea. The loch is 
simple in conformation, and relatively deep, one-half of the lake-floor 
being covered by more than 20 feet of water. The surface temperature 
was 45°*0 Fahr. 
