640 PLATEAU ON THE PHENOMENA OP A FREE LIQUID MASS 



be considered as exactly cylindrical ; so that in this manner we 

 obtain a liquid cylinder, the length of Mhich is from 80 to 100 

 times its diameter, and attached by its extremities to solid parts, 

 which cylinder preserves its form so long as it remains impri- 

 soned between the strips of glass. Weights are next placed 

 upon the parts of the two copper wires which project beyond 

 the extremities of the bands, so as to maintain these wires in 

 firm positions ; lastly, by means which we shall point out pre- 

 sently, the two strips of glass are raised vertically. At the same 

 instant, the liquid cylinder, being libei'ated from its shackles, 

 becomes transformed into a numerous series of isolated spheres, 

 arranged in a straight line in the direction of the cylinder from 

 which they originated*. Ordinarily the regularity of the system 

 of spheres thus obtained is not perfect ; the spheres present dif- 

 ferences in their respective diameters and in the distances which 

 separate them ; this undoubtedly arises from slight accidental 

 causes, dependent upon the method of operation ; but the dif- 

 ferences are sometimes so small, that the regularity may be con- 

 sidered as perfect. As regards the number of spheres corre- 

 sponding to a cylinder of determinate length, it varies in dif- 

 ferent experiments ; but these variations, which are also due to 

 slight accidental causes, are comprised within very small limits. 

 51. Let us now complete the description of the apparatus, 

 and add some details regarding the operations. As the plate of 

 glass requires to be placed in a perfectly horizontal position, it 

 is supported for this purpose upon four feet with screws. A 

 small transverse strip of thin paper is glued to each of the ex- 

 tremities of the lower surface of the strips of glass, in such a 

 manner that the strips of glass resting upon the plate through 

 the medium of these small pieces of paper, their lower surface is 

 not in contact with the surface of the plate. Without this precau- 

 tion, the strips of glass might contract a certain adhesion to the 

 plate, which would introduce an obstacle when the strips are 

 raised vertically. Moreover, the latter are furnished, on their 

 upper surface and at a distance of 6 millims. from each of their 

 extremities, with a small sci'ew placed vertically in the glass with 

 the point upwa-ds, firmly fixed to it with mastic, and rising 

 8 millims. above its surface. These four screws are for the pur- 



* We may remark, that the conversion of a metallic wive into globules by 

 the electric discharge, must undoubtedly be referred to the same order of 

 phaenomena. 



