712 PLATEAU ON FIGURES OP EQUILIBRIUM OF A LIQUID MASS. 



sounds produced by the shock of the disturbed portion are sub- 

 ject. However, it is by boiTowing one of Savart's ideas, which 

 becomes applicable when, from some external cause, vibrations 

 are really excited in the liquid, that we find the elements requi- 

 site for entering upon the latter part of the theory. 



87- In the next series, after having concluded what relates to 

 the vein, we shall return to the liquid masses free from gravity ; 

 and we shall study the other figures of revolution besides the 

 sphere and the cylinder, as also those figures which do not be- 

 long to this class, for which the equation of equilibrium may be 

 interpreted in a rigorous manner. 



