CENTRIFUGAL NOZZLES 215 



beneath the plants. In all these the same letters indicate corresponding 

 l)arts, and it should be noticed that in the last three the outlet is through 

 the large end of the hollow, cup-shaped plug, while it is beveled so 

 deeply that the inner edge is sharp. If this iedge is made to project a 

 little into the chamber, it will be still more free from clogging. These 

 jets will receive attention again farther on as combinations in several 

 machines. While they are the best for poisoning the under surfaces of 

 plants, there are some others which might be substituted for the same 

 purpose and work well enough to be worthy of a notice in this connec- 

 tion. 



Whistle- JETS. — We have introduced another spraying principle in 

 what we call tvhistle-jets, examples of which will now be noticed. 



Plate XXIV, Fig. 7, shows an eddy-chamber nozzle, with a peripheral 

 discharge, s, from the chamber, c, which is closed by a removable lid, plug, 

 or cap, and has a supply-pipe, a x. The axis of the chamber is prefera- 

 bly at a right angle with the axis of the spout, a, and the diameters of 

 these two parts are about equal. But the tangential inlet-hole from the 

 spout through the wall of the chamber is smaller than the caliber of 

 the spout and is situated close to that side which is marked x. The 

 spray is discharged at right angles to the spout, and may be directed 

 horizontally or vertically (upwards or downwards). The internal work- 

 ing and manner in which the spray is generated can be better under- 

 j^tood by reference to Plate XXIY, Fig. 6, which represents a i)lan sec- 

 tion of a nozzle having the same internal arrangement, though with the 

 diameter of the rotation cavity, c, much greater in comparison with that 

 of the spout, «, a disproportion advisable in very large nozzles of this 

 kind. The arrows show the general course of the fluid or powder blast, 

 and it will be seen that the ingoing current is made to bend around 

 to cut through itself to some extent in order to get out through the 

 hole at s. This internal colliding on the intercepting of the outgoing 

 and ingoing parts of the current causes the two to cut each other up 

 into a fine spray, discharged at s. It is prelerable to make the excur- 

 rent hole have its side toward x depressed lower than the opposite yide. 



This intersection principle we have already seen as applied in slot- 

 nozzles in the foregoing pages and in Plate XVI. The confl.iction of 

 two streams outside of a nozzle we have already noticed in Plate XY, 

 Fig. 5, and in descriptions. But one superiority of the present method 

 over these is very evident. The discharge hole being single may have 

 more than twice the capacity of either one of the pair of outlets in the 

 others referred to, hence there is less possibility of choking. Because 

 of this and on account of one current stopping the other, half of the time 

 with a rapid succession of intervals, the outlet can be twice as large as 

 if it threw a continuous jet, and larger still becatfse the jet thrown is not 

 a solid one, but already broken considerably before passing through the 

 outlet. Thus, since only a fraction of the capacity of this hole is used by 

 the volume of liquid thrown, the hole may be two or more times larger 



