16 
BULLETIN 852, U. S. DEPARTMENT OF AGRICULTURE. 
■Open to air. 
2"+6"WJ.P/pe 
-C.I. PJutj; brojed. 
fF/'bre washer. 
^■5cre>v cop 
*Woi/ hole r 
ECScobey. 
Fig. 2.— Method of attaching mercury manometers to concrete pipes. Details of manometers, fluorescein 
gun, and combined current meter weight and mercury bottle. 
