PEE! 



PRESSURE OF AIR OX FLOATING BODIES. 



269 



pressure upon cd would tend to push the body down 

 nto the liquid, unless counteracted by an equal and 

 >pposite pressure. Xow, the pressure of the atmo- 

 phere acts also upon the liquid surface a b, it is trans- 

 tiitted in the liquid and increases downwards by the 

 Additional weight of a liquid column: at ef the pres- 

 ure is greater than that of the atmosphere at c d by 

 he weight of a liquid column which has ef for its 

 ...ase and the depth of ef below a b for its height, that 

 s, the pressure at ef exceeds that at cd by the 

 /eight of the floating body. Suppose next the whole 

 o be inverted, without any displacement, as in fig. 

 86 B. In this position we have still at c d and 



FIG. 186 i real size 



ic pressure of the atmosphere, but ef is now 

 Igher than a b, and since the pressure now decreases 

 !)m a b towards ef, the pressure upon ef is now less 

 tan upon c d by the same amount as that by which it 

 previously greater ; that is, the pressure upon c d 



