THE FRESH- WATER LOCHS OF SCOTLAND. 
89 
about half a mile from the southern end, based on soundings in 82 and 
83 feet. Within the largest 75-feet basin, and about Ij miles from 
the northern end, is the 100-feet basin, about half a mile in length, 
enclosing the maximum depth of the loch. The areas between the contour- 
lines at intervals of 50 feet, and the percentages to the total area, are 
as follows : — 
Feet. „ 
Acres. 
Per cent. 
0 to 50 " 
571 
52-3 
50 „ 100 
485 
44-6 
Over 100 
34 
3-1 
1090 
100-0 
Loch Eck was surveyed on June 20-22, 1903, when the elevation was 
found to be 66*6 feet above the sea, which agrees closely with the elevation 
determined by the Ordnance Survey officers on June 9, 1863, viz. 66-8 feet. 
Temperature Observations . — Two serial temperatures were taken on 
June 22, 1903, one at 2.30 p.m., in the deepest part of the loch, in 135 feet 
of water, and the other at noon, about a quarter of a mile to the south, 
in 74 feet of water, with the following results : — 
Deepest basin, 
135 feet. 
South of deepest 
basin, Y4 feet. 
Surface 
60°-0 
58°-4 
20 feet 
58°-9 
57°-5 
271 „ 
54°-9 
— 
35 „ 
52°-0 
56°-3 
421 ,, 
— . 
51°-5 
50" „ 
50°-0 
50° -2 
70 „ 
— 
48°-3 
100 „ 
470.8 
— 
130 „ 
46°-5 
— 
The series in the deepest basin shows a range from surface to bottom 
of 13°*5, the greatest fall being one of 4° between 20 and 27 J feet. The 
shallower series shows a range of 10°T in the 70 feet of water, the greatest 
fall being one of 4°-8 between 35 and 42J feet. The “ si^rungschicht ” 
was thus observed nearer the surface in the deepest basin, the temperature 
at a depth of 35 feet being 4°*3 lower than at the same depth in the 
shallower water to the south, while at 50 feet the temperature was 
practically the same in both series. A strong south-east wind was blowing 
at the time these observations were taken, which might explain the higher 
readings at the surface and at 20 feet in the more northerly position. 
From the following table it will be seen that in the three lochs under 
consideration 372 soundings were taken, and that the aggregate area of the 
water-surface is just over 2 square miles, so that the average number of 
soundings per square mile of surface is 180. The aggregate volume of 
water contained in the lochs is estimated at 2525 millions of cubic feet. 
The area drained by these lochs is nearly 43 square miles, or 21 times 
the area of the lochs. 
