CAPILLARY MOVEMENT OF SOIL MOISTURE. 



11 



tank can be determined after the lid is placed in position. Around 

 the outside and at the top of the tank is soldered a galvanized iron 

 channel, three-eighths inch wide and three-quarters inch in depth. 

 This channel is to receive the edge of the cover to the tank. 



The lid of the tank is of material similar to the tank and has the 

 outer edge turned down three-quarters of an inch all the way around 

 to fit into the channel on the tank. Passing through the lid and 



Fig. 1. — Isometric view of open flume connected by wick to supply tank. 



soldered to it is the ell. Into the lid is fitted a f -inch tube through 

 which water may be added to the tank. To support the weight of 

 the ell and to stiffen the lid, two galvanized-iron channels are riveted 

 to the underside of the lid, limning crosswise of the tank. These 

 channels are placed just outside the ell. 



THE ELL. 



The ell is, as the name implies, an elbow used to change the direc- 

 tion of the soil column from the vertical. It extends 6 inches 



