THE FRESH- WATER LOCHS OP SCOTLAND. 275 
basin O23posite the entrance of the Allt Bhreacnais, based on half a dozen 
soundings, the deepest in 68 feet. Silting up has taken place at the 
embouchures of the inflowing streams, notably at the two ends of the loch ; 
to this is evidently due the curious loop in the 25-feet contour at the 
western end. In the south-western angle of the loch, where the Allt 
Grain enters, lies a little basin with a maximum depth of 24 feet, cut off 
from the main loch by the narrows between Eilean Mhic na h-Ainnis and 
the western shore, in which the depth is only a foot. The areas between 
the contour-lines, and the percentages to the total area, are as follows : — 
Feet. 
Acres. 
Per cent. 
0to25 
263 
37-4 
25 „ 50 
214 
30-5 
50 „ 75 
148 
21-1 
Over 75 
78 
11-0 
703 
100-0 
A series of temperatures taken in the deepest 2 >art of the loch at 
6-10 p.m. indicated a uniform temperature of 41°*0 Fahr. from surface to 
bottom. Two surface readings near shore earlier in the day gave 43°*9 
and 44°*1. 
Loclian na Bi (see Plate CXXVI.) lies in Argyllshire near the boun- 
dary of Perthshire, 10 miles from Dalmally and a mile from Tyndrum, the 
road and railway between these places passing along the northern shore. 
It is a shallow loch, trending almost east and west, surrounded by swampy 
ground covered in places with small trees. It is about three-quarters of a 
mile in length, with a maximum breadth of about one-eighth of a mile, and 
covers an area of about 39 acres. The maximum depth of 6 feet was 
observed near the centre of the loch. The volume of water is estimated at 
6 million cubic feet, and the mean depth at over 3 feet. The loch was 
surveyed on May 21, 1903, when the elevation was 823-25 feet above sea- 
level ; the elevation is given on the Ordnance Survey map as 822 feet, but 
the date is not mentioned. 
Loch Ederline (see Plate CXXII.) is situated near the head of Loch 
Awe, and is irregular in outline, trending almost north and south. The 
loch is nearly two-thirds of a mile in length, with a maximum breadth of 
over one-third of a mile, covering an area of about 70 acres, and draining 
an area of over 12 square miles. The basin is simple, though the contour- 
lines are sinuous in character, the maximum depth of 58 feet being 
observed towards the south end. The volume is estimated at 70 million 
cubic feet, and the mean depth at 23 feet. 
It was surveyed on May 22, 1903, when the elevation was found to be 
122'4 feet above sea-level; on June 25, 1864, the Ordnance Survey officers 
determined the elevation as 122'0 feet. The tem 2 )erature of the surface 
water was 51°-0 Fahr. 
