LAND AND SEA BREEZES. m 



in and about the equatorial calms, for instance ; there the air is 

 in a state of rest, and will obey the slightest call in any direction 

 — not so in regions where the trades blow over the land, and are 

 strong. It requires, under such circumstances, a considerable de- 

 gree of rarefaction to check them and produce a calm, and a still 

 farther rarefaction to turn them back, and convert them into a 

 regular sea-breeze. 



252. Hence the scorching land-breeze on the west coast of Af- 

 rica : the heat there may not have been intense enough to pro- 

 duce the degree of rarefaction required to check and turn back the 

 southeast trades. In that part of the world, their natural course is 

 from the land to the sea, and therefore, if this view be correct, the 

 sea-breeze should be more feeble than the land-breeze, neither 

 should it last so long. 



253. But on the opposite side — on the coast of Brazil, as at 

 Pernambuco, for instance — where the trade-wind comes from the 

 sea, we should have this condition of things reversed, and the sea- 

 breeze will prevail for most of the time — then it is the land-breeze 

 which is feeble and of short duration : it is rarely felt. 



254. Again, the land and sea breezes in Cuba, and along the 

 Gulf shores of the United States, will be more regular in their al- 

 ternations than they are along the shores of Brazil or South Africa, 

 and for the simple reason that the shore-wind named in North 

 American waters lies nearly parallel with the course of the winds 

 in their prevailing direction. In Rio de Janeiro, the sea-breeze 

 is the regular trade-wind made fresher by the daily action of the 

 sun on the land. It is worthy of remark, also, that, for the rea- 

 son stated by Jansen, the land and sea breezes in the winter time 

 are almost unknown in countries of severe cold, though, in the 

 summer, the alternation of wind from land to sea, and sea to land, 

 may be well marked. 



255. In Valparaiso, the phenomenon of the sea-breeze is finely 

 developed. Valparaiso is situated near the southern border of the 

 calm belt of Capricorn when it is at its farthest southern reach, 

 which happens in our late winter and early spring — the Southern 

 summer and autumn. This is the dry season, when the sky is 

 singularly clear and bright. The atmosphere, being nearly in a 



