638 PLATEAU ON THE PHiENOMENA OF A FREE LIQUID MASS 



gradually becoming narrower, whilst the dilated portions increase 

 in thickness, the figure remaining a figure of revolution ; at last 

 the constrictions break, and each of the various parts of the 

 figure, which are thus completely isolated from each other, 

 acquire the spherical form. We must add, that the termination 

 of the phaenomenon is accompanied by a remarkable peculiarity, 

 of which we have not yet spoken ; but as it only constitutes, so 

 to speak, an accessory portion of the general phaenomenon, we 

 shall transfer the description of it to a subsequent part of this 

 memoir (see § 62). 



49. It might be asked, why, in the experiment which we have 

 last described, the cylinder is only resolved into spheres when 

 the rapidity of the transference of liquid of which it is composed 

 is diminished. In fact, we cannot understand how a motion of 

 transfei'cnce could give stability to a liquid figure which in a 

 state of repose was unstable. In explaining this apparent pecu- 

 liarity, we must remark, that, as the spontaneous transformation 

 of an unstable cylinder is effected under the action of continued 

 forces, the rapidity with which the phaenomenon occurs ought 

 to be accelerated ; this may be, moreover, easily verified in expe- 

 riments relating to larger and less elongated cylinders ; this same 

 rapidity ought therefore always to be very minute at the com- 

 mencement of the phaenomenon. Now, in the case in question, 

 as the changes in figure occur in the liquid of the cylinder whilst 

 this liquid is animated by a movement of transference, it is evi- 

 dent, from what we have stated, that if this movement of trans- 

 ference is sufficiently rapid, the changes of form could only ac- 

 quire a very slightly-marked development during the passage of 

 the point of the funnel to the mass accumulated at the bottom 

 of the vessel ; so that, the liquid being continually renewed, 

 there will be no time for any alteration in form to become very 

 perceptible to the eye. Hence, so long as the rapidity of the 

 flow is sufficiently gi'eat, the liquid figure will appear to retain 

 its almost cylindrical form, although its length is considerable in 

 comparison with its diameter. On the other hand, when the velo- 

 city of the transference is sufficiently small, there will be time for 

 the alterations in form to take place in a perfect manner, and 

 we shall be able to see the cylinder resolve itself into spheres 

 throughout the whole of its length. 



50. We shall now describe another method of experimenting, 

 which allows us to observe the result of the transformation under 



