154 THE PHYSICAL GEOGRAPHY OF THE SEA. 



ure of the most stupendous works of solid masonry that man has 

 ever seen — the coral islands of the sea. 



294. And thus, by a process of reasoning which is perfectly 

 philosophical, we are irresistibly led to conjecture that there are 

 regular and certain, if not appointed channels, through which the 

 water travels from one part of the ocean to another, and that those 

 channels belong to an arrangement which may make, and, for 

 aught we know to the contrary, which does make the system of 

 oceanic circulation as complete, as perfect, and as harmonious as 

 is that of the atmosphere or the blood. Every drop of water in 

 the sea is as obedient to law" and order as are the members of the 

 heavenly host in the remotest regions of space. For when the 

 morning stars sang together in the almighty anthem, " the waves 

 also lifted up their voice ;" and doubtless, therefore, the harmony 

 in the depths of the ocean is in tune with that which comes from 

 the spheres above. We can not doubt it ; for, were it not so, 

 were there no channels of circulation from one ocean to another, 

 and if, accordingly, the waters of the Atlantic w^ere confined to the 

 Atlantic, or if the waters of the arms and seas of the Atlantic 

 were confined to those arms and seas, and had no channels of 

 circulation by which they could pass out into the ocean, and trav- 

 erse different latitudes and climates — if this were so, then the ma- 

 chinery of the ocean w^ould be as incomplete as that of a watch 

 without a balance-wheel ; for the waters of these arms and seas 

 would, as to their constituents, become, in the process of time, very 

 different from the sea w^aters in other parts of the world, and their 

 inhabitants would perish for the want of brine of the right strength 

 or of w^ater of the right temperature. 



295. For instance, take the Red Sea and the Mediterranean by 

 way of illustration. Upon the Red Sea there is no precipitation ; 

 it is a rainless region ; not a river runs down to it, not a brook 

 empties into it ; therefore there is no process by which the salts 

 and washings of the earth, which are taken up and held in solution 

 by rain or river water, can be brought down into the Red Sea. 

 Its salts come from the ocean, and the air takes up from it, in the 

 process of evaporation, fresh water, leaving behind all the solid 

 matter which this sea holds in solution (^ 239). 



296. On the other hand, numerous rivers discharge into the 

 Mediterranean, some of which are filtered through soils and among 



