358 
BATHYMETRICAL SURVEY OF 
found to be 94*24 feet, as compared with 93*2 feet observed by the 
officers of the Ordnance Survey on July 1, 1870. Loch Lochy contains 
37,726 millions of cubic feet of water, or nearly 50 per cent, more than 
Loch Arkaig, the second largest loch in the basin. 
At the north end a small basin, called Ceann Loch, measuring one- 
half by one-third of a mile, and having a maximum depth of 66 feet, is 
cut off from the main loch by a narrow channel in which the greatest 
depth is 40 feet. 
The main loch is a simple basin, with the U-shaped section charac- 
teristic of glacier-formed lakes. All the contours are continuous, those 
at 50 and 100 feet enclosing areas little less than the total length of the 
loch. The area enclosed by the 200-feet contour measures 6J miles in 
length, by the 300-feet contour 4| miles, and by the 400-feet contour a 
little over 3 miles in length. The 500-feet contour encloses a very 
small area, one-third of a mile long by one-eighth of a mile broad, 
just about the middle of the loch, and includes the deepest sounding in 
531 feet. From opposite the mouth of the river Arkaig to the outflow, 
the loch shallows rapidly and the contours are irregular. 
The following table gives the approximate areas between the 
consecutive contour-lines drawn in at intervals of 100-feet, with the 
percentages to the total area of the loch : — 
0 to 100 feet 
923 acres 
24 '4 per cent. 
100 „ 200 ,, 
937 „ 
24*8 
200 „ 300 „ 
651 ,, 
17-2 
300 „ 400 „ 
571 „ 
151 
400 „ 500 „ 
678 „ 
17-9 
Over 500 ,, 
23 „ 
0-6 „ 
3783 „ 
100-0 
The flat-bottomed character of the basin is indicated by the 
comparatively large area covered by water between 400 and 500 feet 
in depth, an area greater than in the two shallower zones ; the zone 
between 100 and 200 feet, also, is rather larger than the shore zone. 
T einperature Observations — The surface temperature varied from 
43°-5 Fahr. to 42°*1. A series taken on April 29 showed the small 
range from the surface to 425 feet of only 1°*2. It will be seen from 
* During the past twenty years Sir John Murray has taken many temperature obser- 
vations in TiOch Lochy, and has published and discussed the results in the following papers, 
to which the reader is referred for further details: (1) “ On the Effects of Winds on the 
Distribution of Temperature in the Sea- and Fresh-water Lochs of the West of Scotland,” 
Scott. Geogr. Mag.., vol. 4 , p. 345, 1888; (2) “ On the Temperature of the Salt- and Fresh- 
water Lochs of the West of Scotland, at Different Depths and Seasons, during the years 
1887 and 1888,” Proc. Roy. Soc. Edin., vol. 18 , p. 139, 1891; (3) “Some Observations on 
the Temperature of the Water of the Scottish Fresh-water Lochs,” Scott. Geogr. Mag., 
vol. 13, p. 1, 1897. 
