MONSOONS. 373 



Arabia upon the winds is felt in Austria and other parts of 

 Europe, as the observations of Kriel, Lamont, and others show. 

 So, also, do the islands, such as the Society and Sandwich, that 

 stand far away from any extent of land, have a very singular but 

 marked effect upon the Avind. 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 even taken those westerly winds of the 

 Society Islands to be an extension of the monsoons of the Indian 

 Ocean. 



697. Influences of coral reefs upon icinds. — It is a curious thing 

 is this influence of islands in the trade-wind region upon the 

 winds in the Pacific. Every navigator who has cruised in those 

 parts of that ocean has often turned with wonder and delight to 

 admire the gorgeous piles of cumuli, heaped up and an-anged in 

 the most delicate and exquisitely beautiful masses that it is 

 possible for fleecy matter to assume. Not only are these cloud- 

 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. These clouds, under favour- 

 able 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 con- 

 densed into showers, one fancies that they are a sponge of the 

 most delicately elaborated material, and that he can see, as they 

 *' drop down their fatness," the invisible but bountiful hand 

 aloft that is pressing it out. — Maury's Sailing Directions, 7th ed., 

 p. 820. 



698. Monsoons in miniature. — Land and sea breezes are mon- 

 soons in miniature, for they depend in a measure upon the same 

 cause. In the monsoons, the latent heat of vapour which is set 

 free over the land is a powerful agent. In the land and sea 

 breezes, the heat of the sun by day and the radiation of caloric 

 by night are alone concerned. In the monsoons the heat of 

 .summer and cold of winter are also concerned. But could the 

 experiment be made with two barometers properly placed — one 

 at sea and the other on land, but both within the reach of land 

 and sea breezes — they would show, I doubt not, regular altera- 



