250 THE ZOOLOGIST. 



coursed through two arches of 6 ft. and 7 ft. respectively, and 

 with a median pillar between them. ' These were guarded by 

 wire-netting of j-in. mesh, attached to a framework of wood 

 about 15 ft. long by 4 ft. deep. The floor of the race above the 

 netting was temporarily paved with broad boards of white wood 

 held down by large iron weights, for the purpose of showing the 

 Trout as they passed. The deep brown hue of the water, how- 

 ever, rendered this device of little avail. The fine wire-netting, 

 nevertheless, demonstrated one thing, viz. that a great current 

 of water flowed easily through it without interfering with the 

 working of the turbines. Leaves, grass, and debris would 

 necessitate cleaning, but they did not stop the current. Every- 

 thing worked smoothly for twenty minutes, but as not a trace of 

 a Trout was observed, the machinery was stopped. An examina- 

 tion of the tail-race — now in quietude — showed numerous small 

 Trout (of the series put in the turbine-pit) in the shallow part, 

 but none went near the white boards. Amongst them were 

 several larger (7-8 in.), which must either have been in the 

 tail-race previously or passed through the turbine — probably 

 the former. On the fine wire-netting was a single dead Trout, 

 which had been carried against it when in a sickly condition by 

 the current. The same occasionally happened at Stormontfield 

 breeding-ponds in the case of even active but very young fishes. 

 In the pit of the turbine one hundred and fourteen young Trout 

 were captured, besides three which were killed by the hand-nets 

 in the process. As usual, they resisted the powerful suction 

 caused by the turbine, and preferred to remain in the pit. 



(VII.) At 2.25 p.m. thirty young Trout were placed in the 

 perforated box, and lowered to the edge of the other Achilles 

 turbine, one of the most modern type, 48 in. in diameter, and 

 170 horse-power, with eighty to ninety revolutions per minute. 

 In working this and the previous turbine it was found that 

 water escaped in considerable quantity from the upper part of 

 the pit of the turbine, but it was stated that no Trout could 

 pass through. This flow by-and-by became less. The machinery 

 started at 2.47, and in a few minutes the rush of water in the 

 tail-race carried away the left guard so as to leave a gap of 

 20 in., and, as this could not readily be repaired, the experiment 

 was necessarily imperfect. When the box was pulled out of the 



