COMETAEY INFLUENCES. 



motion of rotation, the effect of the blow would be to change either 

 its axis of rotation or the time of rotation, or both one and the 

 other. Its new axis of rotation would have a certain position 

 between its previous axis and that upon which the blow would 

 have made it revolve if it had no previous rotation. The deter- 

 mination of this new axis would be a problem cf no difficulty. 



Such being the immediate consequences of such a collision, it 

 remains to consider what would be its secondary results. 



If a carriage moving uniformly on the smooth surface of a rail- 

 way, or a boat propelled or drawn uniformly on the surface of 

 water, receive an impulse by which its speed is suddenly changed, 

 all loose bodies upon it will be thrown backward or forward, 

 according as its speed is increased or diminished, inasmuch as they 

 do not at first participate in the increase or diminution of velocity 

 imparted to the vehicle on which they are placed. Hence it 

 happens, that if a horse going at speed suddenly retards his 

 motion, or stops, the rider is thrown forward, and if he suddenly 

 starts forward with increased speed, the rider is thrown backwards. 



A similar disturbance of position would be produced by a change 

 of direction of the motion of the vehicle. If it suddenly turn to 

 the right, loose bodies will fall to the left, and vice versa. 



The earth, moving in its annual course round the sun, and at 

 the same time revolving uniformly upon its axis, producing the 

 vicissitudes of day and night and the succession of seasons, must 

 be regarded as a vehicle upon which all loose bodies, such as air, 

 water, and other fluids, animals, and all natural and artificial 

 objects, not planted and firmly fixed in the solid ground, are 

 transported, first round the axis of rotation by the diurnal motion, 

 and secondly, round the sun by the annual motion of the earth in 

 its orbit. Now if, under such circumstances, either of these- 

 motions were to receive a sudden change either in velocity or 

 direction, the fluids composing the atmosphere, and the oceans, 

 seas, lakes, and rivers, not partaking of that change, would, for 

 the reasons explained above, be thrown from their position of 

 relative equilibrium. Violent atmospheric commotions would 

 ensue. The waters of the oceans and seas, thrown from their 

 beds, would inundate the continents ; rivers would change their 

 directions, and either run in new channels or inundate the sur- 

 rounding plains ; lakes would desert their positions, and would 

 flow in any channels open to them, or would flood the surrounding 

 countries. Animals would be precipitated against all solid objects 

 near them, with a force greater probably than that of a cannon- 

 ball. Trees would be torn from their roots ; buildings, especially 

 such as have much elevation, would be overthrown ; and if the 

 change of motion were of a certain intensity, lofty mountain peaks 



