THE FRESH- WATER LOCHS OF SCOTLAND. 65 
looked upon as a distinct lake, but in the foregoing description the two 
lakes have been regarded as one. Many temperature observations were 
taken in Loch Laidon on April 9, 10, 14, 15, and 25, the surface 
readings varying from 38°'8 at 5 p.m. on the 9th to 48°'2 at the head of 
the loch at 1 p.m. on the 10th — a range of 9°-4 in the temperature of 
the water, while the range in the air-temperature during the same 
period was only 5° (from 45°-2 to 50°-2). Two serial temperature 
observations were taken in the centre of the loch, the first at 5 p.m. on 
April 9, when the readings were identical (39°*8) at the surface and at 
depths of 5 and 25 feet, the second at 5.20 p.m. on the 10th, when the 
FIG. 18. LOCH LAIDON. 
(Photograph bp Miss Margaret Murray.) 
surface readings were 39°*8 and 41°, that at 5 feet 39°*7, and that at 
20 feet 39°*4. The surface temperature in Dubh Lochan on April 14 
was 43°-9. 
The western arm of Loch Laidon receives the waters from a small 
loch (Lochan Gaineamhach) lying about 2 miles to the west. This 
loch, and the neighbouring one to the north, were visited on May 20, 
1903, but, as there were no boats on them, they were not sounded. 
They were found to be of the same general character as the other lochs 
of Hannoch Moor — shallow, with stony shores, containing boulders 
and islets, some of the latter with small trees on them. In Lochan 
Gaineamhach, weeds were seen only in some very small bays, but in 
