SALMONOIDS AND TURBINES. 257 



afternoon the case was altered, the upper mill being in active 

 operation. The river consequently was so much lowered that no 

 water flowed over the dam, which was composed of stones with a 

 coping of concrete, the latter also forming the sides of the head- 

 race. The diminution of the river caused the Trout to descend 

 to the deeper pools below the dam. 



(XVII.) At 3.22 p.m. a hundred mixed Trout, as before, and 

 two larger (9 in.) Trout were pushed down the wooden shoot (12 ft. 

 long), which had on one side of the extremity an opening next 

 the turbine. The fishes were thus compelled to escape into 

 the water around the turbine. At 3.25 p.m. a Common Trout, 

 13 in. long, and well-nourished, was also sent down, and the 

 aperture plugged by the brush with its cotton covering. At 

 3.40 p.m. an Eel, 13 in. long, was marked by having the tip of 

 the tail removed, and also put, by aid of the shoot, in the 

 vortex of the turbine, the speed of which was fifty revolutions 

 per minute. In drawing out the brush from the wooden tube for 

 the purpose of inserting the Eel, a small Trout came up un- 

 injured on the top of the cloth covering the fibres. This shows 

 how tenaciously they cling to any place of safety under trying 

 circumstances. After fully half an hour's work the net was 

 found to contain ten small Trout, the largest, a Eainbow Trout, 

 being 6 in. long, and the Eel — all uninjured. The rest either 

 remained in the turbine-pit or escaped by the gaps at the sides 

 of the net. No sign of an injured Trout appeared. 



When the water in the river was lowered in the afternoon by 

 the resumption of work by Mr. Hill's mills above (parts having 

 been under repair), the stones along the foot of the weir at Anna 

 Liffey Mills were left dry, and Mr. Armitstead was able to capture 

 the Trout and the Eel without difficulty. The fishes made 

 off rapidly, as the river became low, for the deeper pools beneath. 

 On the conclusion of the experiments a Pike, about 5 lb. in 

 weight, was noticed swimming upwards in a pool. One of the 

 men, taking an iron pipe, waded into the stream, drove the 

 fish to shallow water, and killed it by blows on the head. It 

 was a male with well developed milt. No food was found in the 

 stomach, and little in the intestines. The removal of water is 

 important in connection with the welfare of the Salmonoids, 

 which are thus placed at the mercy of persons disposed to 



Zool. 4th ser. vol. XV.. July, 1911. x 



