36 WIND-WAVES. 



who made the first attempt to explain the phenomena of 

 the tides, on the principle of the influence of gravitation, 

 the grand agent in the movement of the universe. 



What are called ivind-waves are small at their first origin, 

 commencing with a mere ripple, or,^s the sailors term it, a 

 " cat's-paw." But each wave, as it advances, acquires in- 

 creased height by the continued pressure of the wind. Thus 

 it is that the larger waves are not developed in narrow seas, 

 or where the wind blows off the land ; they require breadth 

 of water and continued pressure for their formation. The 

 greatest waves known are those off the Cape of Good Hope, 

 under the influence of a north-west gale (the storm-wind of 

 that region), which drifts the swell around the Cape, after 

 traversing obliquely the vast area of the South Atlantic. In 

 such gales, the waves attain a height of above forty feet, so 

 that two ships in the trough of the sea, with such a wave 

 between them, lose sight of one another from their decks. 

 Off Cape Horn, also, the waves reach upwards of thirty feet 

 in height. In our own seas, they rarely exceed eight or 

 nine feet. 



The crossing of waves, instead of dividing the water into 

 parallel ridges, causes the pitching and rolling so distressing 

 to passengers and trying to vessels. When more than two 

 series of waves cross one another, they give rise to the term 

 chopping seas. 



Whatever relates to the color of the ocean is a matter on 

 which many and various opinions have been expressed. 

 Very curious is the statement of Martyn, one of the early voy- 

 agers, attributing these changes in the sea to the color of the 

 skies : *' If," he says, " the sky be clear, the sea looks as blewe 

 as saphire ; if it is covered somewhat with clouds, the sea is 

 as greene as an emeralde ; if there be a foggy sunshine, it 

 looketh yellow ; if it be quite darke, like unto the color of 

 indigo ; in stormy and cloudy weather, like blacke sope, or 

 exactly like unto the color of blacke leade." 



