VII 



THE AUTHOR'S THEORY OF THE TIDES 



IN" this chapter I hope to convince the reader that tides 

 are not created in the manner depicted by Newton, 

 that is to say, in antagonism to the principle of equi- 

 librium, but rigorously in accordance therewith. 



In the diagram (Fig. 5) let E represent a planet en- 

 dowed naturally with the property of gravitation. It 

 consists, let us say, of a solid ball 10,000 miles in diam- 

 eter surrounded by an envelope of water five miles in 

 depth, and, as an aid to the imagination, suppose this 

 water frozen to a depth of one mile. Let us now bring 

 into touch with E a second body, M, which has no seas 

 and which, in the outset, possesses no gravitational 

 power. Under these conditions E, of course, will not be 

 in the least affected by M's proximity. But suppose we 

 had a method whereby, as by the turning of a tap or 

 switch, we could charge M with as much of this force as 

 we pleased, and let the current be then turned on. What 

 would be the natural effect upon E? Surely its solid 

 part would immediately begin to sink in its own seas and 

 finally rest upon the inner surface of the ice crust (Fig. 

 6). In other words, the tidal action of M on E would 

 be to depress the seas intervening between them and not 

 to elevate them there at all. Now, if you please, turn on 

 the discharging tap and see what will happen next; 

 obviously the planet E will return to its original condi- 

 tion. 



