364 THE PLAN OF THE EARTH AND ITS CAUSES. 



have believed that there is a hidden continental symmetry which, when 

 discovered, will explain the law that has determined the distribution 

 of land and water on the globe. 



This idea dates from the dawn of geographical science. The early 

 classical geographers noticed how the seas radiated from the Levantine 

 area, and opened to a broad, boundless ocean. They accordingly 

 described the land of the globe as an island, floating on a vast surround- 

 ing sea, whence channels converged toward the hub of the classical 

 universe. This radial plan reappears in the mediaeval wheel maps in 

 which Jerusalem was accepted as the center of the world, whence the 

 main geographical lines radiated like the spokes of a wheel. 



These systems fell forever on the discovery of America, which could 

 not be brought into conformity with the radial plan by even the 

 ingenious devices of mediaeval cartographers, Later on came an even 

 worse blow. Geologists showed that, instead of the land areas being 

 fixed and immutable, they are really more fickle and less enduring than 

 the sea. The distribution of land is therefore constantly changing, 

 owing to local variations in its level.. The discovery of this truth 

 seemed to destroy the very basis of any possible earth plan. Indeed, 

 Lyellism, with its essential doctrine of the alternate elevation and 

 subsidence of the land under the agency of local causes, seemed incon- 

 sistent with the existence of any general cause governing the geo- 

 graphical evolution of the globe as a whole. 



But a truer appreciation of this later knowledge did not confirm 

 these first deductions. America is now used as the typical or, to borrow 

 a biological phrase, the schematic continent. And when, remembering 

 the probability of local variations in land level, allowance is made for 

 them, new resemblances are revealed, and exceptions that once were 

 serious difficulties are removed. For instance, the oceans all end in 

 triangles pointing to the uorth. This is the case with the Pacific, the 

 two sections of the Indian Ocean, and the basins of the Mediterranean. 

 The Atlantic alone is broadly open at its northern end. But Scotland 

 and Iceland are connected by a submerged ridge, which is said to be 

 capped by a line of old moraine. If this ridge were raised to sea level, 

 the Atlantic would conform to the general rule by tapering northward 

 to a point between Iceland and Greenland. 



Similarly with the land masses. There seems at first sight no resem- 

 blance in shape between the Old World and the New. But the Old 

 World is divided into halves by a band of lowland, which extends 

 southward from the Arctic Ocean to the Caspian, and northward from 

 the Arabian Sea up the Persian Gulf. There is evidence to show that 

 the sea recently covered these northern lowlands and occupied the 

 Persian depression; while somewhat earlier, in Miocene times, the 

 intervening ridge was also submerged. Restore these conditions, and 

 the continents would occur as three meridional belts, each broken 

 across by transverse Mediterranean seas, viz, North and South America 



