140 The Bed of the Ocean. 



from the centre of the oceanic basin towards its margin — 

 and also why the axis of a submarine plateau is generally- 

 found to coincide with an axis of volcanic eruption and a line 

 of volcanic islands. In accordance with this view, we may- 

 conclude that where there are several ranges running parallel 

 with the coast, the one nearest the coast will be of more recent 

 origin than those further inland. 



Several other phenomena, the explanation of which has until 

 now been a matter of controversy, might be quoted in support 

 of the oceanic origin of the dry land, but their discussion belongs 

 more to the domain of geology than to that of physical 

 geography. It is a significant fact that the results of recent 

 microscopic examination of the materials which compose the 

 different geological formations has led to a partial revival of a 

 favourite theory of the early geologists — namely, the theory 

 of the aqueous origin of rocks in opposition to the theory 

 of their volcanic origin. 



As the air of the atmosphere and the water of the ocean are 

 distributed and renewed by a system of combined horizontal and 

 vertical circulation, so the solid matter which composes the 

 earth-crust is distributed and accumulated through the agency 

 of oceanic currents, and also of atmospheric currents, but chiefly 

 of the former, thus undergoing an unceasing process of disinteg- 

 ration and reformation. To borrow an expression from the 

 studio, water is the vehicle in which Nature dissolves her colours ; 

 while the ocean with his broad brush lays down the ground- 

 tints of her pictures, the atmosphere with a more delicate pencil 

 puts in the finishing touches. 



Marcus Ward & Co., Royal Ulster Works, Belfast. 



