of Edinburgh, Session 1885-86. 
415 
In the Tarbet basin a salient feature is the greater mixture of 
waters at Inversnaid than at either Kowardennan or Stuckgowan, 
the curves at the latter localities being much steeper than at Inver- 
snaid. The same phenomenon was observed on the 18 th August. 
But, perhaps, the principal feature in the Tarbet basin is that both 
at Inversnaid and at Stuckgowan the water at and near the bottom 
has risen in temperature by 0 o, 2 B., or from 41° *8 to 42° *0 since the 
22nd September. As the temperature of the bottom water at these 
localities was 41 0, 8 on the 5th September, it is probable that it had 
been so during the summer, and it is only by the end of September 
or beginning of October that the summer heat begins to have any 
effect on the water near the bottom. The steepest gradients are at 
Kowardennan and Stuckgowan between 20 and 30 fathoms. With 
a view of further investigating this body of water, I returned on 
16th October to the Kowardennan and Stuckgowan stations, and 
took the temperature at 20, 22 J, 25, 27 J, and 30 fathoms, using, at 
20 and 30 fathoms, the same thermometers as had been used the 
day before. As the temperatures at 20 and 30 fathoms were found 
very different from those observed the day before, the observations 
in the Rowardennan locality were repeated close to the east side of 
the loch, the usual station being nearer the west side. The follow- 
ing table gives the temperatures observed on 16th October and also 
the corresponding ones of 15th October. 
Table YI . — Temperatures on Steepest Gradient at Rowardennan and Stuclc- 
goivan, 1 6th October 1885. 
Locality, . j 
Rowardennan. 
Stuckgowan. 
West Side. 
East Side. 
West Side. 
Date, 
Oct. 15. 
Oct. 16. 
Oct. 16. 
Oct. 16. 
Oct. 16. 
No. of 
| Depth. 
Thermo- 
Temperature (Fahr.). 
' meters. 
0 
49T 
49-0 
48-9 
49*1 
49°0 
20 
47 
48-95 
47-8 
47-6 
48-8 
48'4 
22J 
9 
47-4 
46-4 
47-3 
25 
79 
46-55 
46-0 
47-0 
27i 
80 
45-3 
45-5 
46-75 
30 
21 
42-45 
45-2 
45-25 
42-9 
44-5 
These results go to accentuate the fact borne out by all the obser- 
