180 Prof. Magnus's Hydraulic Researches. 



Jets moving vertically upwards, or inclined at any angle to the 



horizon . 

 176. Hitherto only those jets have been considered which 

 flow from above downwards. All others, whether moving verti- 

 cally from below upwards, or at any inclination to the horizon, 

 behave quite similarly. All jets which issue from a perfectly 

 circular opening are smooth and continuous close to the open- 

 in"-; at a greater distance they become turbid, and then have a 

 greater diameter, separating at the same time into distinct drops. 

 On examining the turbid portion by means of the rotatmg slit, 

 the formation of the drops is seen to take place in a manner 

 quite similar to that described in § 156, of streams flowing from 

 above downwards, which are represented in fig. 11. The dimen- 

 sions alone are somewhat different ; that is, the distances of the 

 rounded masses from one another are smaller. 



177. If the efflux-orifice, or the stand on which the vessel or tube 

 is fastened bearing this orifice, is set in vibration by means of a 

 sounding body, swelHngs arc formed in these streams also in 

 exactly a similar manner as in streams flowing vertically down- 

 wards. But the swellings so formed are never so regular as in the 

 former case, because the efflux takes place under a greater pres- 

 sure, and is therefore less uniform. On examination by means of 

 the rotating slit, these swellings behave, it is true, so far similarly 

 to those formed in streams flowing vertically downwards as they 

 consist of separate greater drops which change their form ; but 

 the smaller drops occurring between each two of the larger ones, 

 described in § 159, are often entirely absent, or they are often 

 so irregularly disposed as not to move either in tlie middle be- 

 tween two of the greater ones, or in the same curve with them. 



Separation of the jet into two or three parts. 



178. At a certain inclination of the stream to the horizon, 

 which may be different for the different pressures at which the 

 water flows out, the larger drops often do not all pursue their 

 paths in the same curve. They are then spread through a larger 

 space, and give rise to the appearance which Savart* has called 

 the " Garbe." 



179. This phsenomenon is doubtless due to the very small 

 motions communicated to the efflux-orifice perpendicularly to 

 the direction of the stream by the vibrations of the sounding 

 body, and which may be called transversal motions. 



Although these motions cannot be detected by the eye, they 

 may be recognized by the hand. The efflux-orifice used in my 



* Loc. cit. p. 380. 



