250-251] 



WAVE -PATTERN. 



457 



on the down-stream side then approximates to the form investigated in Art. 

 228, except that the curve, after approaching the axis of as near the origin, 

 runs back along the asymptotes. On the up-stream side we have approxi- 

 mately 



jD = 6sec 2 (i), 



where b = \a cos 4 a. This gives 



251. Another problem of great interest is the determination 

 of the nature of the equilibrium of a cylindrical column of liquid, 

 of circular section. This contains the theory of the well-known 

 experiments of Bidone, Savart, and others, on the behaviour of a 

 jet issuing under pressure from a small orifice in the wall of a 

 containing vessel. It is obvious that the uniform velocity in the 



