318 
BATHYMETRICAL SURVEY OF 
of the bottom between the two deep basins. The cross-section G-H 
is taken at the position of the deepest sounding, and shows a slight 
rise of the bottom off the western shore from 80 to 75 feet. This 
section shows a steep offshore slope at both sides of the loch, but more 
especially off the eastern shore, where a sounding in 78 feet was taken 
about 80 feet from shore, and this steep slope off the eastern shore 
is continued to the northward, where a sounding in 48 feet was taken 
about 60 feet from shore. The soundings taken on the rise between the 
two deep basins indicate a rather uneven floor ; for instance, one line 
of soundings from west to east shows that the bottom sinks gradually 
from the western shore to 86 feet, then rises to 60 feet, sinks to 
75 feet, rises to 30 feet, sinks slightly again to 32 feet, and then rises 
towards the eastern shore ; a little farther south a sounding was taken 
in 40 feet between two deeper soundings (54 and 57 feet). 
The following table gives the approximate areas between the 
consecutive contour-lines, and the percentages to the total area of 
the loch : — 
0 to 
50 
feet 
012 
acres 
38 
per cent. 
50,, 
100 
522 
32 
100 „ 
150 
>5 
246 
,, 
15 
>> 
150 „ 
200 
200 
>> 
12 
Over 
200 
> 5 
49 
3 
> 5 
1629 
100 
Temperature Observations . — Many observations of the temperature 
of the surface water in Loch Laoghal were taken on September 26, 27, 
and 29, 1902, and two serial temperatures were taken on September 29, 
one in each of the two deep basins. The surface temperature varied 
from 52°*5 to 53°*6 Fahr. The serials gave the following results: — 
Depth in feet. 
Deepest part of loch. 
Sept. 29, 1902, 
noon. 
Southern deep basin. 
Sept. 29, 1902, 
2 p.in. 
° Fahr. 
° Fahr. 
0 
53-0 
53 ’6 
10 
52 ’5 
53-4 
15 
52 4 
20 
52 5 
25 
52-5 
52-9 
27*5 
52-6 
30 
53-6 
35 
52-2 
40 
52-4 
50 
52-5 
52-4 
70 
52 4 
52-3 
100 
52-4 
52-5 
125 
50-9 
135 
47-8 
52-3 
145 
46-7 
150 
46-5 
195 
46T 
