108 OUR HERITAGE THE SEA 



to the influence exerted by the wind upon the sur- 

 face of the ocean. It is a curious fact that even the 

 fiercest of conflicting currents, unaided by the wind, 

 is unable to produce more than a series of eddies, 

 certainly nothing important enough to consider as 

 waves; but even a moderate breeze blowing across 

 the set of a fairly strong current will suffice to raise 

 what sailors significantly call an " ugly " sea, meaning 

 one that does not run truly or regularly, and is 

 therefore dangerous. 



Before going any farther, however, it will be well 

 to point out in this connection the nautical use of the 

 word "sea." The sailor scarcely ever uses the word 

 " wave ; " why, I do not know. Instead of saying that 

 a heavy succession of waves were running up from 

 the sou'-west, he says that a heavy sou'-west sea 

 was running. He never says the waves were high 

 or breaking, but that the sea was high or breaking, 

 the ship taking heavy seas aboard, strong wind and 

 following sea, and so on. Therefore if in what follows 

 I drop into the vernacular and use the word " sea " in 

 its nautical sense, I hope it will not be misunderstood. 



I suppose that everybody knows that the cause 

 of all ordinary waves is the pressure of the wind 

 diagonally along the surface of the water. When 

 there is no wind the sea surface is smooth and glassy, 

 but always more or less undulatory, as if with the 

 gentle heaving of some gigantic breathings far beneath. 

 This is called the swell, sometimes in the calm follow- 

 ing or preceding a heavy gale forming huge knolls of 

 mirror-like water, and causing a vessel to roll or pitch 

 heavily, and sometimes so slight as to be hardly 

 perceptible, unless an attempt be made to steady a 



