WITHDRAWN FROM THE ACTION OF GRAVITY. 663 



it follows that the measure of the two configuring forces corre- 

 sponding to these points will be respectively -5- ( tT +^57)3 ^^^ 



^Qr+^)= 1- y(-1 +w)- Thus, in passing from the 

 first to the second figure, the intensities of the elementary con- 

 figuring forces in all the phases of the transformation will be to 

 each other in the inverse proportion of the diameters of the 

 cylinders. 



I have convinced myself, by means of cylinders of mercury 

 r05 millim. and 2'1 millims. in diameter (§ 54 and 55), that the 

 duration of the phaenomenon increases, in fact, with the diameter ; 

 although the transformation of these cylinders is effected very 

 rapidly, yet we have no difficulty in recognising that the dura- 

 tion relating to the greater diameter is greater than that which 

 refers to the least. 



64. As regards the law which governs this increase in the 

 duration, it would undoubtedly be almost impossible to arrive at 

 its experimental determination in a direct manner, i. e. by mea- 

 suring the times which the accomplishment of the phsenomenon 

 would require in the case of two cylinders of sufficient length to 

 allow of their being respectively converted into several complete 

 isolated spherules, and of their satisfying the conditions indi- 

 cated at the commencement of the preceding section. In fact I 

 can hardly see any method of realizing such cylinders without 

 giving them very minute diameters, like those of our cylinders 

 of mercury, and then their duration is too short to allow of our 

 obtaining the proportion with sufliicient exactness. 



But we may be able to arrive at the same result, but with cer- 

 tain restrictions, which we shall mention presently, by means of 

 two short cylinders of oil formed between two discs (§ 46) ; there 

 is nothing to prevent these cylinders from being obtained of such 

 diameters as to render the exact measure of the durations easy. 

 In the transformation of a cylinder of this kind, only a single 

 constriction and a single dilatation are produced ; but as in the 

 transformation of cylinders which are sufficiently long to furnish 

 several complete isolated spheres, the phases through which the 

 constrictions and the dilatations pass are the same for all, we 

 need only consider one constriction and one dilatation. We can 

 understand that the relative dimensions of the two solid systems 

 ought to be such, that the relation between the distance of the 



