236 



THE OCEAN. 



[Book X. 



Because, whatever be the distance from the sun's 

 centre from which the revolving force acts, causing 

 the sun to rotate in the plane of its equator, the velocity 

 which it tends to give to matter in the plane of the 

 equator is checked by the connection of the latter with 

 that extending to the polar regions ; because the force 

 acting from the opposite sides, w and e (Fig. 20), 

 exactly neutralise each other at the poles, n and s, 



and have each their greatest effective action along the 

 equator ; therefore the direct force of the sun's gra- 

 vitation acting from the opposite hemispheres, n and s, 

 towards the centre, c, causes those opposite hemi- 

 spheres to act as a break, retarding the normal velo- 

 city which the revolving force would otherwise give 

 to the equatorial regions.^ 



^ The geological action of this retarding force is alluded to in 

 several parts of The New Principles of Natural Philosophy. 



