148 WAVE IMPACT ON 



ments showed conclusively that under favourable circum- 

 stances water-hammer is set up by wave impact on an open 

 joint, and experiments were then carried out to determine 

 the magnitude of the pressures obtained in the experimental 

 pipe line. 



The velocity of the jet (12-6 feet per sec.) was practically 

 constant throughout the whole series of experiments, and was 

 as high as could be obtained from the available supply. This 

 velocity is equivalent to a face pressure p of 154 Ibs. per 

 square foot. The mean results of the experiments, corrected 

 for the frequency of the applied force, are as follow : 



(a) Experiments in which the phenomena are essentially 

 due to air compression. 



(6) Experiments in which the phenomena was due to 

 water-hammer. 



(1) Jet played into horizontal pipe. 



