﻿986 Dr. Thomas on Discharge of Air through Small 



that the effect referred to is not so pronounced in the case of 

 jets issuing from the longer channels. The same is seen from 

 curves 4 A and 5 A in fig. 8. 



The existence of turbulence in the jet naturally suggests 

 itself as the cause of the phenomenon referred to. It is clear 

 that as the effect occurs only over a limited range of pressures, 

 and is not present at the higher pressures employed in the 

 present series of experiments, and as moreover the mean 



< 3 









^ 



5A^ 



• 









— ~~"~~~2A 









** JA 





17 







figa 















5 10 15 



PRESSURE (CMS OF WATER] 



20 



25 



velocity in the jet for this range of pressures is considerably, 

 below the critical velocity at which turbulent flow occurs, 

 the turbulence referred to is impressed upon the jet on 

 entering the orifice. It is therefore to be anticipated that 

 the effect would be less pronounced in the case of long- 

 channels than in the case of small channels, as in the former 

 case the unstable turbulence initially impressed upon the 

 stream would die away to a greater extent than in the 

 latter case. This, as has just been stated, was found to be 



