Page:Africa by Élisée Reclus, Volume 4.djvu/363

 CLIMATE OF MOZAMBIQUE. off the coast, under the latitude of Ibo, there occurs the dangerous marine bank of St. Lazarus, where vessels have occasionally been wrecked, although it is covered mostly by depths of from 6 to 18 fathoms. Climate. On the Mozambique coast the south-east trade-winds have so little force that they are frequently deflected from their normal course by the centres of intense radiation, developed at one time on the mainland to the west, at another on the great island of Madagascar to the east. Moreover the broad Mozambique Channel, which is disposed in the direction from north-east to south-west, offers to the atmospheric currents an easy passage, which they usually follow, setting either northwards to the equator or southwards to the Antarctic seas. The trade winds prevail most frequently during the cooler months, that is, from April to Sep- tember, when the vertical solar rays strike the globe north of the equator. Nevertheless, even during this season the aerial currents are generally deflected towards the north. They sweep round the south coast of Madagascar, and on reaching the Mozambique Channel set steadily northwards in the direction of Zanzibar. But from October to March, when the sun has moved to the southern hemi- sphere, followed by the whole system of atmospheric currents, the prevailing winds on the Mozambique coast are those blowing from the north-east. They set parallel with the seaboard in the same direction as the marine current itself, which now acquires a mean velocity of from about 2 to 4 miles an hour. In these maritime regions hurricanes are extremely rare. Fully forty years have elapsed since one of these atmospheric disturbances has been witnessed, when in January, 1841, a terrific cyclone churned up the Mozambique waters, tearing the shipping from its anchorage and strewing the coast with the wreckage. During the two following years Mozambique was again visited by similar storms, and on each occasion at the same period. Flora and Fauna. The moisture precipitated in the basins of the Rovuma and the other coast streams north of the Zambese is not sufficiently copious to nourish a luxuriant vegetation. Great forest-trees matted into an impenetrable tangled mass by trailing or twining plants are met only on the banks of the running waters. But although the coastlands have no large growths except on the irrigated tracts, the thickets on the elevated terraces are none the less very difficult to traverse. Here the brushwood and small shrubs are often so inextricably interwoven that it might be possible to walk for hours without once touching the ground. Caravans that have to force their way through this underwood move very slowly. The porters have to cut themselves a passage beneath the overhanging branches, avoiding the sharp points of many a projecting root, and in some places even creeping on all 116— AF