of Vibratory Motion in Fluids. 



437 



Rsr. 4. 



der of the same liquid, it continues in an unbroken line for 

 8 inches or more, having the diameter of the smallest part. 

 Recalling a deduction of Fronde's, that a liquid flowing through 

 a tortuous tube without friction has no tendency to straighten 

 it, I mounted the jet on pivots, and, by giving 

 it an oscillatory motion, found that the stream 

 travelled the liquid as a perfect wave, showing 

 the deduction to be experimentally true. This 

 apparatus (fig. 4), if mounted on the board car- 

 rying the vibrating lever and water-jet, gives a 

 graphic representation of the wave which is pro- 

 ducing the figures (figs. 2 and 3), and shows 

 the presence or absence of harmonics. 



By using in the glass cylinder a weak solu- 

 tion of oxalic and sulphuric acids, and supplying 

 the jets with a solution of sulphuric acid and 

 permanganate of potash of exactly the same 

 density, the waves are extinguished after a few 

 seconds, while the liquid remains quite clear. 

 It will be seen that the streams (figs. 2 and 3) 



soon break into beads. On receiving these in 



water, they manifest the spheroidal state in a high degree. 



When the bubble of air in the air-chamber (fig. 1) is above 

 a certain size it splits into several lesser ones; and these on 

 entering the current have a less velocity than the water towards 



the jet. Fig. 5 shows how this effect 



may be magnified. In a glass tube of 



5-inch bore, the limb A is about 1 foot 



long and closed at C. An india-rubber 



tube is attached at E, and bent back 



at a small angle in order to vibrate, 



as in the Bunsen pump. B is the 



waste-pipe. A bubble of air, the 



size of a rape-seed, is placed in the 



bend at F, A being full of water. 



When the current of water through E 



causes the whole to vibrate, the air- 

 bubble detaches itself from the tube, 



takes the shape of a string of four or 



five beads, and sinks through the water 



to C, where it remains as long as the 



vibration continues. Attempts were 



made to substitute sphericles of glass, 



shellac, wax, &c, each made a little 



lighter than water, but without suc- 

 cess. If the result were due to the 



