20 THE LIFE OF THE SALMON 
to make arrangements for a series of observations 
by means of a boom-net used in fishing for sparlings 
or smolts (osmerus). This net is worked from a 
smack anchored in the channel; the mouth when 
extended by its booms and the pressure of the 
current is 24’x 18’. Operations were commenced a 
short distance below the mouth of the Earn, where 
we had on the previous season lost trace of the 
smolts, and were continued down the estuary at 
intervals till a point was reached below the Tay 
Bridge and opposite the city of Dundee, the essential 
feature being the working of the net in the channel 
or fairway. This fishing yielded most interesting 
results. The net was set forty-six times, and salmon 
smolts were now captured freely. Some 1085 young 
salmonids were taken, and the great majority of 
these were salmon smolts, the others being sea 
trout. 
Two points were specially noticeable :— 
1. As the descent of the estuary was made, the 
size of the salmon smolts did not increase. 
2. All salmon smolts captured were taken when 
the net was set so as to fish the ebbing tide. When 
the net was set so as to fish the flood tide or incoming 
current sea trout were alone taken, and many of 
these were nearly twice the size of the salmon smolts. 
Sea trout were also taken during ebb tide. 
The natural inference from those observations 
seems to be that, after congregating in great numbers 
at the extreme upper limit of the brackish water, 
the salmon smolts make a steady and comparatively 
rapid descent to the open sea, without hanging about 
