The universal geography : earth and its inhabitants

24
^YEST AFRICA.
gystomatic exploration of the Atlantic, which constitutes their title to renown
durinj^ the ape of the great nautical expeditions. On this occasion they saw
nothing l)iit the reefs of Formigas between San-Miguel and Santa-Maria ; but
Goncalo \'elho f'abral, returning to these waters next year, discovered Sauta-Maria
itself, which Don Henri presented to hini as a iief. Twelve years afterwards he
landed on San-3Iiguel, the chief island in the archipelago, which he also received
in vassalage under the Portuguese crown. The eastern group of Cabrera, or Las
Cabras, had already formed part of geographical nomenclature, but another twenty
years passed before the last of the nine members of the group was finaUy sur-
veyed.
Although scattered, over a vast space, the islands have many features in
common. All are hilly and dominated by volcanic craters whence lava streams
have been discharged, and all terminate seawards in rugged masses of black scoria
pjw 10.—Volcanic Axis of the Azoees.
Depths,
to 3,300 Feet, 3 300 Feet and upwards.
* Submarine Volcanoes.
presenting a forbidding aspect. "With the exception of Santa-Maria, at the south-
eastern extremity, which contains some limestone beds dating from the Miocene
period, all are composed exclusively of ashes, scoria?, and lavas. Geographically
tlicy form three perfectly distinct groups, of which the easternmost is the largest,
although comprising only the two islands of San-Miguel and Santa-Maria, with the
reefs of Formigas, which may be regarded as the crests of a submerged rocky islet.
The central group consists of five members—Terceira, which has at times ffivcn
its name to the whole archipelago ; Graciosa, San-Jorge, Pico, and Faval. The