THE FRESH-WATER LOCHS OF SCOTLAND. 
93 
nearly in tbe broadest part. It is of small extent (a quarter of a mile 
long), and has a greatest depth of 58 feet. At the date of the survey 
(July 10 and 11, 1903) the surface was 673’3 feet above sea-level. This 
was considerably higher than when surveyed by the Ordnance Survey 
(though the elevation is not given on the 6-inch maps), and the outline 
of the loch, especially in the southern portion, was greatly altered in 
consequence. 
A series of temperatures taken near the deepest part of the loch showed 
a range of 4°-6 Fahr., as shown in the following table : — 
Surface ... 
10 feet ... 
25 „ ... 
50 „ ... 
80 „ ... 
59°-6 Fahr. 
58°'9 „ 
58°-0 „ 
56°-8 
55°*0 
n 
Derclach Loch (see Plate XXXV.). — A very small, narrow, and shallow 
loch, lying close to the west of Loch Finlas. It is a little over half a mile 
long, one-eighth of a mile broad, and 12 feet deep. The bottom at the 
deeper part is flat, and 10 feet deep over a considerable area. The 
maximum of 12 feet is close to the west end; the eastern part is very 
narrow, irregular, and from 1 to 6 feet deep. The mean depth is feet, 
the area 38 acres, and the volume 12 millions of cubic feet. The area 
drained is scarcely a square mile. No important stream enters, and the 
burn flowing east to Loch Finlas is only about 100 yards long. The 
shores are of peat and gravel, with rock exposed at several points. 
The surface was 837*15 feet above sea-level on July 13, 1903. The 
temperature was 58°*4 Fahr. throughout. 
Loch Finlas (see Plate XXXV.). — A small, narrow, dumb-bell-shaped 
loch, with a straight axis running north-west to south-east, lying among 
moorland, Ij miles to the west of Loch Doon. The hills on the north 
rise to a little over 1000 feet (200 feet above the loch) ; on the south they 
are higher, Craiglee attaining a height of 1716 feet. The loch is IJ miles 
long and one-third of a mile broad in the north-western expansion. The 
channel connecting the ends of the loch is three-quarters of a mile long, 
for the most part less than 100 yards broad, and varies in depth from 
6 to 18 feet in the centre. The north-western expansion is the deeper. 
The bottom is irregular, with the maximum depth of 40 feet in the centre, 
but other soundings up to 34 feet close inshore. The south-eastern ex- 
pansion is much shallower, and nearly flat-bottomed, with a depth of about 
10 feet, and a little depression of 26 feet at the end of the strait. The 
mean depth is nearly 10 feet, the area about 138 acres, and the volume of 
water 58 millions of cubic feet. The area drained is nearly 5 square miles. 
The natural outflow is by the Garpel burn, issuing from the east end of 
the loch ; but the water is now utilized as the water supply for the town 
of Ayr. The surface was 829*65 feet above sea-level on July 13, 1903, 
