2 8o APPARATUS FOR FISHING. 



and catches in the gill opening, from which it cannot easily 

 be cleared without more or less injury to the fish. In 

 drift-fishing then the floating nets act as barriers to inter- 

 cept the moving shoals, and the fish become meshed in 

 their attempts to pass through. 



Long experience has shown that certain conditions are 

 favourable to drift-fishing. It will of course be easily 

 understood that the more indistinct the net is in the water, 

 the more likely the fish are to swim against it and to 

 become meshed. The night is, therefore, with very rare 

 exceptions, the time chosen for drift-fishing ; and it is 

 noticed that just after sunset and just before sunrise, when 

 the change is taking place from light to darkness, or the 

 reverse, herrings especially are most likely to " strike " the 

 net, as it is called. This is one point among many in 

 connection with the habits of the herring which cannot at 

 present be explained. A ripple on the surface of the 

 water is also a favourable condition for fishing, and this 

 will be readily understood ; for if the surface of the sea be 

 at all broken, such, light as falls upon it, be it ever so little, 

 is reflected or turned off by every little wave, and therefore 

 does not penetrate to the nets so as to make them visible. 

 During the last few years some very interesting observa- 

 tions have been made on the coast of Scotland on the 

 temperature of the sea whilst the herring-fishing has been 

 going on, and its possible relation to a successful fishery. 

 The late Marquess of Tweeddale, who was President of the 

 Meteorological Society of Scotland, provided a number of 

 deep-sea thermometers to be used by the fishery officers 

 and the fishermen for the purpose of testing the tempera- 

 ture of the sea at different periods of the fishery. The 

 Committee who had charge of the experiments state that 

 the conclusions arrived at so far must be considered as 



