THE FRESH- WATER LOCHS OP SCOTLAND. 
69 
shallow, the maximum depth being 20 feet, and the mean depth feet. 
The superficial area is abouLl84 acres, of which 74 per cent, is covered by 
less than 10 feet of water. The volume of water is estimated at 61 
million cubic feet, and the drainage area extends to 30 square miles. The 
elevation above the sea could not be determined, but the Ordnance Survey 
maps give it as 1024 feet, though the date is not indicated. 
There are three basins in which the depth exceeds 10 feet : one at the 
east end enclosing the maximum depth of the loch (20 feet), one in the 
central part of the loch having a maximum depth of 12 feet, and one at 
the west end having a maximum depth of 16 feet, taken close to a 
promontory projecting from the northern shore. 
Temperature Observations . — Serial temperatures taken in the deepest 
part of the loch on May 19, 1903, gave the following results : — 
Surface . . . 
10 feet ... 
15 „ ... 
53°-0 Fahr. 
50°-0 „ 
46^-2 „ 
46°-0 „ 
The range of temperature from surface to bottom was 7°, the greatest 
fall being one of 3°'8 between the depths of 10 and 15 feet. 
LocJian na Shlach TJidhre (see Plate XXVI.). — This loch lies to the 
west of Loch a’ Bhaillidh, and is most irregular in outline, consisting of 
several divisions varying in size, connected by short channels. The two 
easternmost divisions could not be surveyed, being cut off from the main 
loch by a narrow channel, with a fall of about 5 feet. There is also a 
slight fall of 6 inches to a foot in the channel leading into the westernmost 
division of the loch, though the Ordnance Survey maps give the same level 
(1022 feet above the sea) for the entire loch west of the falls. On the 
whole, the loch is shallow, with many islands and boulders. The length 
of the portion surveyed is nearly 2 miles from east to west, and the 
maximum breadth over one-third of a mile. The area is about 245 acres, 
of which 86 per cent, is covered by less than 10 feet of water. In nine 
places soundings deeper than 10 feet were taken, mostly restricted areas 
varying from 10 to 12 feet in depth, and only in three places were depths 
of 20 feet and over recorded: (1) in the narrower portion between the two 
peninsulas called Rudha Dubh-mor and Rudha Dubh-beag at the east end, 
where a sounding in 20 feet was taken ; (2) to the west of Rudha Dubh- 
beag, where soundings in 22 and 26 feet were taken ; and (3) in the 
westernmost division, where soundings in 23, 25, and 29 feet (the maximum 
depth recorded) were taken. The volume of water is estimated at 70 
million cubic feet, and the mean depth at 6J feet. The area draining 
directly into the loch is nearly 9 square miles, but as it receives the 
overflow from Loch a’ Bhaillidh, the total drainage area is about 38J 
square miles. 
Tem'perature Observations , — ^Serial temperatures taken on May 19, 1903, 
