42 POPULAR LECTURES AND ADDRESSES. 



I now pour in water, and we find the flexible 

 bottom assuming very much the same shape as the 

 drop which you saw hanging from my finger after 



t 



FIG. 27. Section of the air bubble in a level tube filled with water, and bent so 

 that its axis is part of a circle of large radius ; scale is represented in Fig. 28. 



it had been dipped into and removed from the 

 vessel of water (see Fig. 16, p. 39, above). I con- 

 tinue to pour in more water, and the form changes 



FIG. 28. Represents a length of one centimetre for Figs. 24 to 27. 



gradually and slowly, preserving meanwhile the 

 general form of a drop such as is shown in Fig. 

 15, until, when a certain quantity of water has 



