266 
BATHYMETRICAL SURVEY OF 
Geal Loch (see Plate CXXIV.) is a small simple basin lying at the head 
of Loch Lomoncl, into which it drains. It is one- third of a mile in length 
in a north and south direction, and covers an area of about 28 acres. The 
maximum depth of 23 feet was recorded towards the northern end, the 
mean depth being estimated at nearly 10 J feet, and the volume of water at 
12 million cubic feet. 
Loch Shy (see Plate CXXIV.) is situated about 3 miles south-west from 
Ardlui, and about 2 miles to the west of the upper part of Loch Lomond, 
the mighty Ben Vorlich rising between them ; while to the west of Loch 
Sloy rises Beinn Dubh, and to the south-west Ben Voine and other lofty 
peaks. The floor of the loch is rocky, and the hollow in which it rests has 
probably been filled up to a large extent by boulders fallen from the steep 
slopes of Ben Vorlich and Beinn Dubh ; the outflowing stream flows over 
solid rock, and the bed of the loch is undoubtedly a rock basin. The loch 
trends from north-west to south-east, and is extremely elongate in outline, 
being over a mile in length, but only one-eighth of a mile in maximum 
breadth. The superficial area is about 65 acres, of which about 73 per 
cent, is covered by less than 10 feet of water, and the drainage area is 
extensive, exceeding 6 square miles. The maximum depth of 31 feet was 
recorded near the southern end, the mean depth being estimated at over 
8 feet, and the volume at 23 million cubic feet. The floor of the loch is 
irregular, there being two 10-feet basins, the larger, over half a mile in 
length, occupying the southern portion of the loch, separated from the 
smaller, a quarter of a mile in length, by a ridge covered by 1 and 2 feet 
of water. The loch was surveyed on June 11, 1903, but the elevation 
above the sea could not be determined ; judging from spot-levels it 
appears to be about 810 feet above sea-level. 
Kilhirnie Loch (see Plate CXXXII.) is a broad oblong sheet of water in 
the county of Ayr, between the villages of Kilbirnie and Beith, 16 miles 
from Glasgow. It lies entirely in cultivated land, the G. and S.W. Bail way 
skirts its eastern shore, and the southern end is occupied by ironworks 
and chemical works, the debris from which encroaches upon the loch. The 
length is over 1^ miles, and the greatest breadth is fully one-third of a mile. 
The loch is shallow, more than half the area being covered by less than 
10 feet of water, and the mean depth is 9f feet. The west side is shallow, 
a depression running parallel to the east shore, in which there are two 
holes of 24 feet and 30 feet respectively. The area is about 247 acres, or 
nearly two-fifths of a square mile, and the volume of water 105 millions of 
cubic feet. The drainage area extends to about 2 square miles. The Maich 
burn is the chief feeder, entering at the north end. The outflow is by the 
Dubb’s burn, which flows from the north-east corner of the loch northward 
by the bed of the Barr Loch (now drained) into Castle Semple Loch. 
On the date of the survey (July 26, 1906) the surface was 100*3 feet 
above sea-level. 
