136 THE LIFE OF THE SALMON 
are of great interest as showing that in each case 
the lower river which flows from the large loch into 
the sea has a markedly higher temperature than the 
river above the loch. It is noticeable also, when the 
charts which were prepared * are studied, that the 
curves representing the mean weekly temperature 
of the Ness and Awe (the lower rivers) are more 
uniform in line or less quickly fluctuating than are 
the curves for the upper waters. The Ness curve 
during January, February, and March shows a 
wonderfully flat inclination. The temperatures were 
taken November 1901 till end of May 1902. I will 
refer first to the Garry and Ness readings. From 
the middle of December to the end of March the 
weekly mean of the Garry never exceeds 40° F., and 
in the middle of February, when the river was very 
low after four weeks of continuous frost, the reading 
reaches 35°. In April and May there is a steady 
rise of temperature. The curve for the Ness runs, 
however, at a distinctly higher level. In December, 
January, February, and March there is constantly 
from 2° to 8° difference in the readings. By the 
middle of April the temperatures of the two rivers 
have approximated by the rise in temperature found 
in the Garry, the upper and early river. On referring 
now to the curves representing the Orchy and Awe 
temperatures, we notice first a much greater fluctua- 
tion in both curves, but the same general result. 
The Orchy is colder by 2° to 9° than the Awe, and 
by the middle of April the curves approximate by 
* Twenty-first Annual Report, Fishery Board for Scotland, IT. 
p. 76, 
