field. Although average water depth at the weir site during this test 

 had increased to 15„1 inches, only 1,192 watts were required to ener- 

 gize the array. 



(c) With a spacing of 8 feet between the electrodes of each 

 row, minimum voltage gradients between elements of the "A" and "B" rows 

 averaged 0„6U volt per inch. Sea lampreys were now observed to penetrate 

 and pass through the entire electrical field and continue their journey 

 upstream. Average water depth at the device during this test was 15.1 

 inches 5 960 watts were required to energize the array. 



In the second method, in which incremental fields were pro- 

 duced by removing every other electrode from the "C" row while at the 

 same time the full AC line voltage was applied across the "A" and "B" 

 and the n B" and "C" rows, the following results were obtained from the 

 single test performed (U-foot interval between rows of electrodes in the 

 array) : 



(d) With electrodes of the "A" and "B" rows set on U-foot cen- 

 ters and those of the "C rt row set on 8-foot centers, minimum voltage 

 gradients between electrodes of the "A" and "B™ rows were in excess of 

 0.75 volt per inch, A complete blockade of the sea lamprey run was 

 effected comparable to that created in Test (a) above. Average water 

 depth at the weir during this test was 1$.9 inches ; 2,U25> watts were re- 

 quired to energize the array, 



Comparison with Test (a) 'above indicates that under comparable 

 stream conditions, power requirements for developing an incremental field 

 by this method are approximately one-third greater than for that developed 

 by the first method discussed. 



Uniform electrical fields were produced with both 3-row and 

 2-row suspended electrode systems by applying the full AC line voltage 

 (110) across the "A" and "B" and the "B" and "C" rows of the 3-row system 

 or simply across the two rows of a 2-row system. Where the 3-row elec- 

 trode system was tested at Squaw Creek, the following results were ob- 

 tained (interval between rows of electrodes in the array was 3 feet); 



(e) With a spacing of 3 feet between electrodes in each row, 

 minimum voltage gradients between electrodes of the n B" row and those of 

 the "A" and "C" rows averaged 0.86 volt per inch. Sea lampreys were 

 unable to penetrate any portion of the array. Average water depth at the 

 weir site during this test was 8.9 inches J 197 watts were required to 

 energize the device. 



Where the 2-row electrode system was tested in the Kewaunee 

 River, the following results were obtained (interval between the two rows 

 was k feetj in effect, only the "B" and "C" rows of the original 3-row 

 installation were used) i 



33 



