THE WINDS. 281 



wich, that stand far away from any large extent of land, have a 

 very singular but marked effect upon the wind. They interfere 

 with the' trades very often, and turn them back ; for westerly and 

 equatorial winds are common at both these groups, in their winter 

 time. Some hydrographers have taken those westerly winds of 

 the Society Islands to be an extension of the monsoons of the In- 

 dian Ocean. Not so : they are local, and do not extend a great 

 way either from the Sandwich or Society Islands. 



That they are local about the former group, an examination of 

 sheet No. 5, Pilot Chart North Pacific, will instantly show. 



812. It is a curious thing is this influence of islands in the 

 trade-wind region upon the winds in the Pacific. Every naviga- 

 tor who has cruised in those parts of that ocean has often turned 

 with wonder and delight to admke the gorgeous piles of cumuli, 

 heaped up and arranged in the most delicate and exquisitely beau- 

 tiful masses that it is possible for fleecy matter to assume. Not 

 only are these piles found capping the hills among the islands, but 

 they are often seen to overhang the lowest islet of the tropics, and 

 even to stand above coral patches and hidden reefs, "a cloud by 

 day," to serve as a beacon to the lonely mariner out there at sea, 

 and to warn him of shoals and dangers which no lead nor seaman's 

 eye has ever seen or sounded out. 



813. These clouds, under favorable circumstances, may be seen 

 gathering above the low coral island, and performing their office 

 in preparing it for vegetation and fruitfulness in a very striking 

 manner. As they are condensed into showers, one fancies that 

 they are a sponge of the most exquisite and delicately elaborated 

 material, and that he can see, as they " drop down their fatness," 

 the invisible but bountiful hand aloft that is pressing and squeez- 

 ing it out. — Mauey's Sailing Directions^ 7th ed., p. 820. 



814. It would appear, therefore, that these desert countries ex- 

 ercise a powerful influence in checking and overcoming the force 

 of the northeast trade-winds. There are no such extensive influ- 

 ences at work checking the southeast trades. On the contrary, 

 these are accelerated ; for the same forces that serve to destroy the 

 northeast trade-winds, or retard them, tend also to draw the south- 

 east trade-winds on, or to accelerate them. Hence the ability of 



