270 
BATHYMETRICAL SURVEY^ OF 
C-D is taken across the loch in the position of the deepest sounding. 
The areas between the consecutive contour-lines drawn in at equal 
intervals, and the percentages to the total area of the loch, are as 
follows : — 
0 to 50 feet 
658 acres 
28-6 per cent. 
50 „ 100 „ 
00 
UO 
25-2 „ 
100 „ 150 ,, 
418 „ 
18-1 
150 „ 200 „ 
272 ,, 
11*8 
200 „ 250 „ 
220 „ 
9-6 
Over 250 ,, 
155 ,, 
6-7 
•2305 „ 
100 0 
The regularity of the average slope of the bottom is indicated by 
the gradually decreasing areas between the contour-lines, and the 
comparatively large area within the deepest contour indicates the 
flat-bottomed character of the deeper part of the loch. 
Loch Fannich was surveyed on August 13 and 14, 1902, and the 
elevation of the lake-surface was found, on commencing the survey, to 
be 821-9 feet above sea-level, which is identical with the level observed 
by the Ordnance Survey on May 27, 1870. 
T emperature Observations . — The temperature of the surface water 
during the two days spent on the survey varied from 52°'7 Fahr. to 
58°-l. Two serial temperatures were taken on August 14, 1902, with 
the following results : — 
Depth in feet. 
August 14, 1902, 
4 '15 p.m. 
Deepest part of loch. 
August 14, 1902, 
5-30 p.m. 
South-east ctf Rudha 
MOr. 
° Pahr. 
° Fahr. 
Surface 
53-0 
54 0 
5 
52 0 
10 
51-9 
20 
51 6 
53 0 
40 
52-5 
50 
51-0 
70 
50-0 
100 
48 -6 
46-7 
130 
45-7 
150 
45-6 
2fX) 
44-9 
250 
44-5 
281 
44-4 
Each of these series shows a range from surface to bottom of about 
8J°. The temperature was higher in the upper 40 feet of water towards 
the west end of the loch than in the deep water towards the east end, 
but at the depth of 100 feet the temperature was 2° lower in the former 
position. Off Rudha Mor there was a fall of 2°-5 between 40 and 70 
feet, and a further fall of 3°*3 between 70 and 100 feet (equal to 5°-8 in 
