Cobb. — Protecting Migrating Pacific Salmon. 153 



drop of low amperage, and a voltage of 110 to 120, connected to 

 the spirals or electrodes will furnish ample electricity. If a 

 power line is not available, electricity may be supplied by a small 

 generator driven by a water wheel or gas motor. Copper wiring 

 is connected to the tops of the electrodes, and electrical current 

 is shot in all directions through the canal in a zone of about 

 twelve feet up and down the ditch, and the County game au- 

 thorities claim this is sufficient to turn back all fish entering. 



The writer has visited these devices a number of times, but 

 has not yet been fortunate enough to witness the actions of fish 

 when coming into the charged zone. Those, however, who have 

 witnessed them claim that as the young fish drift tail first down 

 the stream they are seen to be affected when some feet away 

 from the device and immediately swim away from the affected 

 zone. It is said that when the device was first put in and charged 

 young fish were at times seen around the electrodes and the 

 force of the current was sufficient to knock them senseless, but 

 they soon recovered after drifting out of the charged area. 



In 1921 the devices were put in the ditches several weeks 

 after the water had been turned in and thus it was impossible 

 to tell whether the very few fish found in the ditches when the 

 water was turned off in the fall had got in before or after the 

 devices were installed. This year, however, the devices were 

 in place when the water was turned in and conclusive evidence 

 of their efficiency will be afforded during the summer and after 

 the water is turned off in the fall. 



Discussion. 



Mr. J. N. CoBB: I am preparing now a comprehensive report on fish- 

 ways of the Pacific Coast. The engineer who has been working with me for 

 some time on this problem under my direction has prepared a number 

 of plans. I am holding the report up until we test out one or two of these 

 devices, but I can assure you that I shall be only too glad to place at the 

 disposal of those who are interested any of the plans prepared. I have 

 gathered, as far as I could, plans and specifications of other fishways, and 

 would like to enlarge this collection. If, therefore, any of the members 

 here know of fishways that I can get plans and specifications of — whether 

 they work or not — I should be glad to hear of them; because I would like 

 to knov/ what is good as well as what it is wise to avoid. I never knew 

 of a fishway that was thoroughly satisfactory, while many of them have 

 been absolutely worthless. 



Mr. Carlos Avery, St. Paul, Minn. : Perhaps we are inclined to give 

 up the struggle with reference to fishways in this section of the country- 



