-«ag-se-:«r»aati' " • Ti»i«i iai^sakir..* 



:>Me J«iaa*)r,.- 



Figure 9. — Drawing a sample of water from a standpipe in 

 order to determine the amount of dissolved 

 oxygen in water seeping through gravel of the 

 Sacramento River. 



Figure 10. — Using the conductivity bridge for determining 

 apparent velocity in the controlled-f low chan- 

 nel at Mill Creek. Operator in background is 

 dropping conductivity cell into the chamber 

 of a standpipe. 



15 



