128 EQUILIBRIUM. 



Recapitulation. In this section we have considered 

 Ineompressibility ; the Transmission of Pres- 

 sure with Explanation and Illustration ; Pas- 

 cal's Law with Argument and Conclusion 

 therefrom; one of Pascal's Experiments ; the 

 Hydrostatic Bellows; the Hydrostatic Press; 

 Downward Pressure with experimental illustra- 

 tions; Rule for computing downward pressure ; Up- 

 ward Pressure with experimental illustrations; 

 Rule for computing upward pressure ; Lateral 

 Pressure with experimental illustrations; Rule for 

 computing lateral, pressure. 



j@aEC.Ti ON H. 



A: 

 EQUILIBRIUM. CAPILLARITY. BOUYANCY. 



232. Conditions of Liquid Rest. The force 

 of gravity tends to draw all liquid particles as near the 

 earth's centre as possible. The following are necessary 

 conditions, that a liquid may be at rest : 



(1.) The free surface of the liquid must be 

 everywhere perpendicular to the force of gravity, 

 i. e., horizontal. In the case of the ocean, this condition 

 is modified by the so-called centrifugal force, which gives 

 rise to the spheroidal shape of the earth. 



(2.) Every molecule must be subjected to equal 

 and contrary pressures in every direction. 



233. Equilibrium of Liquids. A liquid of 

 small surface area is said to be level when all the points of 



