Page:Africa by Élisée Reclus, Volume 4.djvu/361

 grounded in mid-stream. During the periodical inundations there can be no doubt that steamers would everywhere find sufficient depth as far as the firet cataracts,

The Rovuma, which falls into a spacious bay just north of Cape Delgado, has no bar at its mouth; nevertheless, small craft run some risk in penetrating from the sea into the river, owing to the eddies caused by the conflict of the opposing fluvial and marine currents.

The section of the seaboard, extending for a distance of about 300 miles nearly in a line with the meridian, from Mokambo Bay to the Rovuma estuary, presents

a remarkable contrast to the section disposed in the direction from south-west to north-east, extending from Sofalu Bay to the Zambese delta and the Mozambique coast. Southwards the beach is everywhere low and destitute of harbours, whereas farther north the coast is deeply indented with creeks and inlets, while ramifying headlands, continued by islets, stretch far seawards. This striking contrast is explained by the action of the Mozambique current, combined with that of the coral-building polyps. The oceanic stream flows close in shore south of the Rovuma, eating away the foot of the cliffs, striking against the rocky promontories, and sweeping in rapid eddies round every inlet on the seaboard. The bays are thus scoured of all their sedimentary matter, and while the current is accomplishing this work the coralline animalcules are building up their structures in