266 
BATHYMETRICAL SURVEY OF 
South Loch Gown . — The southern loch is roughly quadrangular in 
outline, over half a mile in length, and nearly a third of a mile in 
maximum width, covering an area of about 55 acres, while it drains 
an area exceeding 13 square miles. The maximum depth of 52 feet 
was observed relatively close to the north-eastern shore. The volume 
of water is estimated at 38 million cubic feet, and the mean depth at 
nearly 16 feet. The loch forms a simple basin, the 10-feet contour 
following approximately the outline of the loch and extending a short 
distance into the passage leading to the northern loch, and the 25-feet 
basin is centrally placed. Of the entire lake-floor, only 13 per cent, is 
covered by more than 25 feet of water. It was surveyed on August 2, 
1902, when the elevation was determined as being 524*4 feet above the 
level of the sea. 
North Loch Gown . — The northern loch is more oblong in outline 
than the southern loch, so that while nearly equal in length its 
maximum width is less, viz., about a fifth of a mile. Its waters cover 
an area of about 48 acres, and it drains directly an area of about 
1 square mile ; but, since it receives the outflow from the southern loch, 
its total drainage area is over 14 square miles — nearly 200 times 
greater than the area of the loch. The greatest depth observed was 
17 feet, approximately near the centre of the loch. The volume of 
water is estimated at 14 million cubic feet, and the mean depth at 
nearly 7 feet. A constriction in the outline towards the southern end 
of the loch is accompanied by a slight shoaling of the bottom, the 
result being that a small 10-feet basin near the southern end, with 
a maximum depth of 13 feet, is separated from the large main basin. 
Of the entire lake-floor 22 per cent, is covered by more than 10 feet 
of water. It was surveyed on the same day as the southern loch 
(August 2, 1902), and the elevation was determined as being 522*1 
feet above sea-level. 
Temperature Observations . — Serial temperatures were taken in the 
deepest part of each loch, with the following results : — 
Depth in feet. 
North Loch Gown, 
August 2, 1902, 
1 p.m. 
South Loch Gown, 
August 2, 1902, 
4 p.m. 
° Fahr. 
° Fahr. 
Surface 
55*7 
55*0 
10 
55*7 
55*0 
15 
55*7 
20 
55*0 
30 
53*8 
40 
52*1 
In the shallow north loch the temperature was found to be constant 
from surface to bottom, and in the south loch the temperature was 
constant from the surface down to a depth of 20 feet (though more 
