[farmek] determination OF COEFFICIENT OF DISCHARGE 



47 



the inside surface of the plate is still flusli with that of the vahv. and 

 therefore with that of the whole surface of the tank. It is held in that 

 position b}^ a ring, which is screwed down on it on the side away from 

 the rim. 



When the valve is rotated so as to bring the orifice opposite to the 

 large hole in the side of the tank, the water is fi-ee to issue through the 

 orifice ; but in any other position the valve does not allow any "water to 

 escape. 



The water used is that of the city supply. There are two pipes- 

 through which it can enter the tank. One is o inches in diameter, and 

 is used when it is required to rapidly run a quantit}^ of water into the 

 tank ; as, for instance, when, after using a low head, it is required to 

 make an experiment with a high head. A smaller pipe, H inches dia- 



A 



n 



SECTION 

 .47 A B. 



ELEVATION. 



Vfeufd from 

 inside of Tank. 





Experimental Tank. Fig. 2. 



meter, serves to supply water to take the place of that which is discharged 

 during an experiment. There is another smaller pipe Avhich will be 

 referred to and described in connection with the arrangements for adjust- 

 ing the head of water exactly to any required height. Each of the two 

 large pipes is controlled by a stop-valve, and is arranged to deliver the 

 Avater into the chamber of the tank below the false bottom. 



There are two outlets for fast and slow discharge, each connected 

 with the portion of the tank below the false bottom ; these are used in 

 case it is required to reduce the quantity of water in the tank. There is- 



