Prof. Magnus's Hydraulic Researches. 179 



fig. 21 this appearance is represented. The drop a, which is 

 divided by the wire V, is very plainly seen^ but it is generally 

 situated somewhat below P, as is shown in the figure. It is 

 clear that the drop can only be seen on the wire P if the revolv- 

 ing slit passes before the eye at the exact moment when the drop 

 is upon P. Inasmuch, however, as the distance between two of 

 the great drops is very much greater than their diameter, the 

 sht passes before the eye very much oftener when the wire P is 

 situated in the interval between the drops than in the interval 

 when a drop is passing by. Hence the divided drop is seldom 

 seen on the wire, but generally when it is already beneath it. 



Deviation of the jet on the approach of an electric body, 



172. If an electric body, such as a rubbed rod of glass or 

 rosin, be approached to a jet which has no swellings at the part 

 where it is still quite continuous, the jet is defl^ected somewhat 

 as is shown in fig. 22, in which E E represents the electric rod, 

 A B the vertical, and BCD the deflected part of the jet. 



173. If, in a similar manner, the electric rod be approached 

 to the middle of a regular swelling when the electric action is of 

 a certain strength, it is only the internal narrow cylindrical part 

 r s- of the stream which is defiected ; so that this portion separates 

 entirely from the swelling, somewhat as is shown in fig. 23. 



1 74'. That is, the small drops which form the internal cylin- 

 drical part, are much more easily attracted by the electric body 

 by induction than are the greater drops which give the outer 

 form to the swelling ; so that the lesser ones are deflected from 

 their path, but not the greater ones. This deflection occurs with 

 every small drop in the same mauner and at the same place ; 

 consequently they all pursue the same direction, and produce 

 thereby the impression of a narrow curved stream, just as, with- 

 out deflexion, they produce that of a narrow vertical cylinder. 

 So great, howevei', is the regularity of the motions of the stream, 

 that the lower swellings appear still quite unaltered after the de- 

 flection of the small drops. 



175. On the approach of an electric body, besides the regu- 

 larly-deflected internal cylinder, sometimes distinct streams of 

 water proceed out of the swellings, which are as fine as threads 

 of glass, and, like these, follow the electric body. They are 

 formed out of the fine drops which, as mentioned in § 159, 

 sometimes spirt out laterally from the swellings when the note 

 producing the swellings is not pure, or, which is the same, when 

 two inharmonious notes are sounded simultaneously. 



N 2 



