256 THE ZOOLOGIST. 



condition of these turbines comparatively few Smolts could find 

 entrance into the turbine-pit if the wire-netting is left intact. 

 The removal of some of the strands, however, may admit some 

 into the chamber. One difficulty in experimenting with these 

 turbines was the backwater and flooded condition of the tail-race. 



The succeeding experiments were made at the Anna Liffey 

 Mills (corn and flour) of Messrs. G. Shackleton and Son, October 

 2nd, 1900. The supply of water comes from the Liffey by an 

 oblique and rather long dam, from the lower angle of which a 

 deep (6-8 ft.) head-race, about 8 ft. broad, runs to the first 

 building (wood), where the race is guarded by strong iron bars, 

 which seem to have been originally about 3 in. apart. It flows 

 through, turns to the left, and reaches the turbine-pit after a fall 

 of 6| ft. The turbine is an Alcott, 60 in. in diameter, and of 

 forty horse-power, with fifty to fifty-two revolutions per minute. 

 Here, as elsewhere, considerable difficulty was experienced in 

 fitting on the net at the tail-race, close to the exit of the water 

 from the turbine, this position being chosen so as to minimise 

 the chance of the Trout escaping observation in the tail-race, 

 which had to be reached by crawling under beams after descend- 

 ing the ladder at the turbine. Notwithstanding the energetic 

 efforts of Mr. Shackleton, Junior, a gap of about a foot was left 

 at each side of the net. 



(XVI.) At 1.57 p.m., on October 2nd, 1900, fifty small Trout 

 from 4 in. to 5 in., and consisting of a mixed series of Loch- 

 leven, Eainbow, Brook, and two large Eainbow Trout of 9 in., 

 were placed in the long wooden tube, the lower end of which was 

 close to the *' gates " of the turbine, and all were pushed out by 

 the brush with its cover of cloth. In half an hour the net was 

 examined and five living Trout secured, besides two Parr of 

 6-7 in., which did not pertain to the official series. Doubtless 

 others escaped through the meshes of the net, or by the gaps at 

 the side. No dead fish was observed. 



Mr. Shackleton stated that he had seen Smolts coming down 

 the river tail first, then enter the head-race, become suspicious, 

 turn back, and finally go over the weir. Salmon swim up the 

 water over the weir, not leap up, in a full river. 



During the forenoon the mill above this {viz. Mr. Hill's) was 

 not working, so that a full supply came downward, but in the 



