130 



REPORT OF THE PISH AND GAME COMMISSION. 



Fig. 78. Oliver filter at the Potrero plant of the Pacific Gas and Electric Company, San 



Francisco. Photograph by A. M. Fairfield. 



Fig. 79. Kelley filter-press of Pacific Gas and Electric Company at Oakland. Butters filter 

 at San Jose. Butters filter, Potrero plant of Pacific Gas and Electric Company 

 at San Francisco. Butters filter at Oakland. Photographs by A. M. Fairfield, 



