394 PHYSICAL GEOGRArnY OF THE SEA, AND ITS METEOROLOGY. 



eastern, in a nortli-eastwardlj direction, and that, as they ap- 

 proach the shores of this ocean on the east, tliey again turn down 

 for lower latitudes and wanner climates. This feature in them 

 indicates, more surely than any direct obseiTations uj)on the 

 currents can do, the presence, along the African shores in the 

 North Atlantic, of a largo volume of cooler waters. These are 

 the -svaters which, having been first heated up in the caldron 

 (§ 72G) of St. lioque, in the Caribbean Sea, and Gulf of Mexico, 

 have been made to run to the north, charged with heat and 

 electricity to temper and regulate climates there. Having per- 

 formed their offices, they have cooled down ; but, obedient still 

 to the " Mighty Voice " which the winds and the waves obey, 

 they now return by this channel along the African shore to^be 

 again replenished with w-armth, and to keep up the system of 

 beneficent and wholesome circulation desio-ned for the ocean. 



CHAPTER XYIII. 



§ 740-772. TIDE-EIPS AND THE SEA DRIFT. 



740. TJie glories of the sea, and the destiny of the nautilus. — We 

 never tire of the sea ; like the atmosphere, it is a laboratory ;in 

 which w^onders by processes the most exquisite are continually 

 going on. Its flora and its fauna, its weaves and its tides, its currents 

 and its salts, all in themselves afford profitable subjects of study 

 and charming themes for thoiTght. But as interesting as they are 

 individually, and as'' marvellous too, they are not half so mar- 

 vellous, nor nearly so wonderful as the offices which, with their 

 aid, the sea performs in the physical economy of our planet. In 

 this aspect the sea, wdth its insects, its salts, and its vapours, is a 

 machine of the most beautiful construction. Its powers are vast, 

 multitudinous, and varied. It is so stable and true in its work 

 that nothing can throw it out of gearing, and yet its compensa- 

 tions are so delicate that the task of preserving them is assigned 

 to the tiniest of its inhabitants, and to agents apparently the 

 most subtle and fickle. They preserve its harmonies and make 

 its adjustments, in beauty and sublimity of efiect, to vie with 

 the glories of the heavens. Take the tiny little nautilus, one of 

 the oldest families in the sea, for example. Where, inquires 

 M. Lucien Dubois, do they go in such fleets with their purple 



