SWIRLS OF THE SEA. 



25 



Even at the present time humanity has dif- 

 ficulty in compreliending that the earth is solid, 

 that it is far greater in bulk than the sea, and 

 that its hollows and depressions hold the sea 

 as in a shallow dish. Superficially looked at 

 the water has many times the bulk of the 

 dish, but not the less it is the dish that 

 sustains. It holds the water and holds it with 

 a flat surface. When the wind blows the surface 

 is ruffled; when the dish itself is shaken the 

 water is rocked into tidal waves. But these are 

 momentary disturbances. Generally speaking 

 the surface is smooth and practically flat. 



Flat but not everywhere level though it looks 

 so to the eye. In sea musings when gazing out 

 upon the great plain we are continually re- 

 minded of the saying about " water seeking its 

 level " ; but it would seem as though the saying 

 were more familiar than accurate. There is, 

 for instance, a variation between the levels (not 

 the tides) of the Atlantic and the Pacific at 

 Panama which has been vaguely regarded as a 

 possible difficulty in the way of the proposed 

 inter-oceanic canal. There is also considerable 

 variation in the mean sea level owing to dif- 

 ference in atmospheric pressure over differ- 

 ent localities. And again local disturbances 

 such as winds, may alter the level tempo- 



Extent of 

 land and 

 water. 



Sea level 



