140 



THE WINDWARD COAST. 



Atlantic islands Tenerife and Madeira, is com- 

 posed of gently rolling hills. Yet seven fathoms 

 are often found within a stone-throw of the 

 land, whilst the encircling ledges are steep -to, 

 marked in the charts m and m. Evidently, then, 

 the corallines are perched upon the summits of a 

 submarine range which rises sharp and abrupt 

 from abysmal hollows and depressions. As usual 

 too in such formations, the leeward shore line of 

 the island, where occur the lagoon entrances, is 

 more varied and accidented than the eastern. 

 At Pemba this feature will be even more re- 

 markable. 



The windward coast, in common with many 

 parts of the continental seaboard, suffers espe- 

 cially from June to August from the Has de 

 Maree (Manuel de la Navigation et la Cote occi- 

 dental de l'Afrique), a tide race, supposed to 

 result from the meeting of currents. It is a line 

 of rollers neither far from nor very near the 

 shore. The hurling and sagging surf is described 

 to resemble the surge of a submarine earth- 

 quake ; and the strongest craft, once entangled 

 in the send, cannot escape. It would be useful 

 to note, as at West African Lagos, the greater or 

 less atmospheric pressure accompanying the phe- 

 nomenon, and to seek a connection between it 



