80 



The diagram shows the position of this gate which is placed on the up- 

 stream or inlet side of the box. The pressure of the water tends to push 

 the gate away from the gate frame and cause leakage. To prevent this the 

 gates, which are named pressure gates to distinguish them from the cheaper 

 slide gates, are so designed that when the gate is closed turning the handle 

 brings the gate tight againsT its frame. This is obtained through some 



