THE FRESH- WATER LOCHS OF SCOTLAND. 
63 
The temperature of the surface water near the boathouse, when com- 
mencing the survey at 2.45 p.m. on April 17, was 50°-8 Fahr., but 
later on, out in the open water, the surface temperature was 44°*2 
Fahr. ; on the 18th at noon the surface temperature near the shore 
was 50°-0 Fahr., while in the bay to the north of the boathouse the 
temperature was 46°'0 Fahr. 
Lochan Beinn Caorach and some other small basins of water in 
FIG. 17. — herons’ nests on eilean molach in loch BA. 
(PliotO(jrai)h by T. N. Johnston, M.B., C.M., F.R.S.E.) 
this region were without boats and could not be sounded; they were 
evidently all quite shallow and of the same character as Loch Buidhe. 
Loch Laidon (see Plate XVII.). — Loch Laidon (or Lydoch, or 
Luydan) lies partly in Perthshire and partly in Argyllshire, the 
boundary running along the centre of the western arm and for a 
certain distance up the main loch. It is one of the best trouting lochs 
