Page:Africa by Élisée Reclus, Volume 4.djvu/362

 deep water off the coast, although even here a ceaseless struggle is maintained between these new formations and the waves of the sea. In one place the reefs are carved into islands, in another the current sweeps away the less compact coral masses, or else hollow out channels and narrow passages through them, where ebb and flow alternate with the velocity of a mill-race.

But south of Mozambique the marine current, ceasing to follow the shore-line, sets far seawards, the consequence being that all the inlets along the coast are gradually choked with sand or mud. According to the observations of sailors navigating these waters, the stream follows its normal direction from north to south for nineteen days in twenty, but its course is at times checked and even arrested, while it has been observed on some rare occasions actually to set in the opposite direction, towards the north.

Between Quelimane and Mozambique the coral-builders have erected a continuous chain of reefs and islets, skirting the coast at a distance ranging from 12 to 18 or 20 miles, and enclosing a broad channel, which in many places affords good anchorage. Natural harbours of refuge follow in quick succession along this marine highway within the reefy Primeira and Angosha (Angoxa ) islets. But at the point where the shove-line takes the direction from south to north, these outer roadsteads are replaced by harbours formed by erosive action on the coast itself, There the port of Mokambo develops an extensive basin where whole fleets might ride at anchor in depths ranging from 60 to 90 feet. Mozambique commands from its low islet a labyrinth of inner havens, followed northwards by Conducia Bay and the magnificent group of sheltered inlets presented by the Ferñao Vellozo or Masasima basin. Memba Bay, with those of Mwambi, Montepes, Ibo, Masimbwa, and Mayapa, not to speak of the many excellent anchorages formed by the islets off the coast, render this seaboard one of the most favourable for navigation in the whole world. At the same time the barrier reefs and the swift currents striking against them require great caution on the part of skippers frequenting these waters. Even 60 miles