Figure 8. Electromechanical weir and trap installed in Squaw 

 Creek in 1952. 



generator). The generators also had adequate reserve power for the 

 operation of utility lights, warning lights, and such floodlights as 

 were used for night time observations. 



(3) Hib bards ' Creek electrical barrier . — This device was 

 composed of two diverse elements! (a) A single row of electrodes sup- 

 ported by an overhead cable which in turn was suspended between single 

 steel towers at each bank, and, (b) a submerged lateral electrode placed 

 on the stream bottom downstream from the suspended electrodes and tra- 

 versing the entire stream width (Fig. 9). The roxtf of suspended elec- 

 trodes consisted of 118 elements of l/2-inch standard galvanized pipe, 

 spaced on U-inch centers, which were hung by short wire rope hangers 

 from a channel iron rail. The spacing between electrodes could be in- 

 creased by U-inch increments for test purposes. Electrode lengths var- 

 ied from 1-1/2 to 5> feet according to the contour of the stream bed. 



17 



