Chap. XXL] THE HEAVENS. 259 



the particles in the plane of rotation, z x, the earth's 

 gravitation inclines them out of that plane into the 

 next parallel of greater circumference, o y, where the 

 centrifugal force is augmented ; and pressing in this 

 manner through each parallel of latitude towards the 

 equator, they replace the particles at E, whose centri- 

 fugal force, augmented by the pressure of the particles 

 from X, carries them towards b and g. 



Thus the water sinks from a to n, glides along the 

 surface of the earth from n to e, and rises upwards 

 from E to (/, 



The centrifugal tendency imparted by the rotating 

 surface of the earth increases as any particle travels 

 from N to E ; but as it rises from e to ^ it gradually 

 loses the centrifugal impetus which caused it to fly 

 off from the surface at E (for its motion is retarded, 

 as shown in Proposition XXV, of the planet moved 

 from the orbit abf to the higher orbit c d ein Fig. 19, 

 p. 88), and as the particles raised up towards g 

 lose their centrifugal force, their gravitation to the 

 earth must tend to restore the equilibrium of the ocean, 

 making the pressure of the column e ^ at e equal to 

 the pressure of n / at n. 



2. As the centrifugal force continues to act on the 

 particles resting on the surface of the earth tending to 

 carry them from N (Fig. 22) through .'c y to e and b, 

 they prevent the particles at g from falling to the 

 earth in a direct line ; and therefore as the centri- 

 fugal force of the particles at x tends to cause them 



