20 
BATHYMETRICAL SURVEY OF 
(5J square miles), and it drains an area nearly ten times greater, or 
about 32,500 acres (nearly 51 square miles). The number of soundings 
taken in Loch Leven was 538, the maximum depth being 83 feet. The 
bulk of water contained in the loch is estimated at 2,195,000,000 cubic 
feet, and the mean depth at less than 15 feet, being 18 per cent, of the 
maximum depth. The length of the loch is 232 times the maximum 
depth, and 1296 times the mean depth. 
An examination of the map shows how uneven the bottom of Loch 
Leven is. The deepest part of the loch is cut up into two portions, the 
larger depression lying to the west and south of St. Serf’s island, with a 
maximum depth of 83 feet — the greatest depth observed in the loch — the 
smaller depression being situated in the north-western part of the basin, 
and attaining a maximum depth of 79 feet. The larger 70 -feet depres- 
sion lies to the west of St. Serf, with two isolated soundings of 70 feet 
farther to the south-east; the smaller 70-feet depression is in the north- 
western part of the loch, with an isolated sounding of 71 feet. The 
larger 50-feet depression to the south and west of St. Serf is nearly a 
mile in length, while the smaller in the north-western portion of the 
basin is a little over half a mile in length. The larger 20-feet depression 
is very irregular in outline, extending from near the outlet of the loch at 
the river Leven along the southern and western shores of St. Serf, and 
sending a wide branch in a westerly direction and another in a north- 
westerly direction towards Castle island, with an extreme length of 
about two miles. It is separated by an interval of about half a mile (in 
which the bottom rises in a pear-shaped elevation — a sunken island — 
covered by 5 to 9 feet of water) from the north-western 20-feet depres- 
sion, which is apparently extremely regular in outline, being about 
two-thirds of a mile in length, and over one-third of a mile in maximum 
width. The 10-feet line follows approximately the contour of the loch, 
except off the eastern shore to the north of St. Serf, where the 10-feet 
line runs on an average nearly three-quarters of a mile distant from the 
shore. The 10-feet line also surrounds Heed Bower, Castle island, and 
Scart island, and in addition to the elevation in the central part of the 
loch already mentioned, there is another small elevation covered by 
depths of 3 to 7 feet near the southern shore off Waterbutts plantation. 
The area of the bottom between the shore and the 10-feet contour- 
line is about 1430 acres, or 42 per cent, of the whole area of the loch ; 
that between the 10- and 20-feet contours is nearly 1450 acres, or 43 
per cent.; that between 20 and 50 feet is about 375 acres, or 11 per 
cent. ; that between 50 and 70 feet is nearly 110 acres, or 3 per cent. ; 
and that over 70 feet is about 25 acres, or 1 per cent. It v/ill thus be 
seen that no less than 85 per cent, of the bottom is covered by less than 
20 feet of water, and the mean depth- as already mentioned is less than 
15 feet. 
The details regarding the physical features of the different lochs are 
collected together in the following table for convenience of reference : — 
