CRAIOEND PONDS. 



245 



the plug for the octagon, or by depressing the upright pipe for 

 either of the 100-feets (Fig. 170). The fish have first been netted 

 out, so far as can be easily done ; and, as a rule, not more than 

 500 are left in either of the 100-feets after several sweeps of the 

 net, in the case of yearlings. The octagon, from its shape, is 

 harder to net clean. As some years each 100-feet yields 12,000 

 yearlings, 500 is a fair proportion for the well to take. For some 

 time after the pond 

 is drawn, few fish de- 

 scend, or, if they leave 

 the pond, they remain 

 in the pipe, swimming 

 against the current. 

 But after a 100-feet is 

 down so low that the 

 iron bolt can be with- 

 drawn, and the elbow FIB. 170 scale A. 

 is drawn forward, the fish can be easily driven to the mouth 

 of the pipe, when they quickly take refuge in its interior. A 

 net then held in the well takes them safely ; or the water, which 

 by this time is much decreased in volume, can be heightened by 

 placing a board across the mouth of the escape-pipe, and so 

 deepened in the well, to assure the fish from injury. In fact, with 

 a small board to heighten the water, a large number of trout will 

 live for hours, and by letting a little fresh water into the 6 -inch 

 pipe fish might be left in the well all night without loss. The 

 screen in the well should be as fine as possible not larger than 

 No. 9 for yearlings so as to reduce the suction, and heighten the 

 water in the well at first when the flow is strongest. All the sizes 

 of the wells, pipes, and screens must be proportioned to each other. 

 When this is the case, everything works smoothly and safely. 



At Middlethird, the boxes were numbered and new zinc placed 

 on the outlets, and the house was ready by the end of November. 

 The hatching-boxes at Howietouri were ready by the middle of 

 October. 



