666 PLATEAU ON THE PHENOMENA OF A FREE LIQUID MASS 



probably that of all other very slightly viscid liquids (§ 60). 

 Thus the law given by the short cylinders of oil will be exactly 

 or apparently that which would apply to cylinders of mercury of 

 sufficient length to furnish several spheres, supposing the latter 

 to be produced in vacuo or in air, free at the whole of their 

 convex surface, and of such length that the divisions in each of 

 them would assume their normal length. Moreover, the same 

 law would be undoubtedly applicable to cylinders formed of any 

 other very slightly viscid liquid, and supposed to be in the same 

 conditions as the preceding. 



The law may possibly be completely general, i. e. it may 

 apply to cylinders formed, always under the same circum- 

 stances, of any liquid whatever ; but our experiments do not 

 furnish us with the elements necessary to decide this ques- 

 tion. Lastly, the transformation of our short cylinders presents 

 a peculiarity which entails another restriction. The two final 

 masses into which a cylinder of this kind resolves itself being 

 unequal, the smallest acquires its form of equilibrium consider- 

 ably before the other, so that the duration of the phaenomenon 

 is not the same. Hence we can only determine its duration 

 up to the moment of the rupture of the line ; consequently the 

 proportion which we thus obtain for both cylinders will only be 

 that of the durations of two homologous portions of the entire 

 transformations. Moreover, the proportion of these partial dura- 

 tions is exactly that of which we shall have hereafter to make use. 



65. I made the experiments in question by employing two 

 systems of discs, the respective dimensions of which were to 

 each other as one to two ; in the former, the diameter of the 

 discs was 15 millims,, and they were 54 millims. apart; and 

 in the second their diameter Mas 30 millims., and their di- 

 stance apart 108 millims. The cylinders formed respectively 

 in these two systems were therefore alike, and, as I have pre- 

 viously stated (§ 63), these two figures exactly maintained their 

 similarity, as far as the eye was capable of judging, in all the 

 phases of their transformations. It sometimes happened that 

 the cylinder, when apparently well formed, was not at all per- 

 sistent and immediately began to alter ; this circumstance being 

 attributable to some slight remaining irregularity in the figure, 

 I immediately re-established the cylindrical form*, and the time 

 was only taken into account when the figure appeared to main- 

 tain this form for a few moments. Another anomaly then some- 

 * See the second note to paragraph 46. 



