SEA ROUTES, CALM BELTS, AND VARIABLE WINDS. 337 



to the tides and currents along that route, the average passage 

 both from Europe and America to our north-west coast was not less 

 than 180 days. It has been reduced so as to average only 135 

 days. Tliis route is now so well established, and the winds of 

 tlic various climates along it so well understood, that California 

 bound vessels sailing about the same time from the various ports 

 of Europe and America are, if they be at all of like prowess, 

 almost ^ure to fall in with and speak each other by the wa}'. 



628. Ohstmctions to the navigator. — The calm belts at sea, like 

 mountains on the land, stand mightily in the way of the voyager, 

 but, like mountains, they have their passes and their gaps. In the 

 legions of light airs, of baffling winds, and deceitful currents, the 

 seaman finds also his marshes and liis " mud-holes " on the watel*. 

 Jjut these, these researches have taught him how best to pass or 

 entirely to avoid. Thus the forks to his road, its turnings, and 

 the crossings by the way, have been so clearly marked by the 

 winds that there is scarcely a chance for him who studies the 

 lights before him, and pays attention to directions, to miss his 

 A\-ay. 



G29. Plate VIII. — The arrows of Plate YIII. are supposed to 

 fly with the wind; the half-bearded and half- feathered arrows 

 denote monsoons or periodic winds ; the dotted bands, the regions 

 of calm and baffling winds. Monsoons, properly speaking, are 

 winds which blow one half of the year from one direction, and the 

 oilier half from an opposite, or nearly an opposite direction. The 

 time of the changing of these winds, and their boundaries at the 

 various seasons of the year, have been discussed in such numbers, 

 and mapped down in such characters, that the navigator who 

 wishes to take advantage of them or to avoid them altogether is 

 no longer in any doubt as to Mhen and where they may be 

 found. 



630. Deserts. — Let us commence the study of the calm belts as 

 they are represented on Plates I. and VIII. The monsoons and 

 trade-winds are also represented on the latter, they often occupy 

 the same region. But, turning to the trade-winds for a moment, 

 we see that the belt or zone of the south-east trade-winds is 

 broader than the belt or zone of north-east trades. This pheno- 

 menon is explained by the fact that there is more land in the 

 northern hemisphere, and that most of the deserts of the earth — 

 as the great deserts of Asia and Africa — are situated in the rear, 

 or behind the north-cast trades ; so that, as these deserts become 



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