When the mariner, amid the islands of some distant archipelago, is no
longer guided by the light of the same stars with which he had been familiar
in his native latitude, and sees himself surrounded by palms and other forms
of an exotic vegetation, he still can trace, reflected in the individual
characteristics of the landscape, the forms of Vesuvius, of the come-shaped
summits of Auvergne, the craters of elevation in the Canaries and Azores, or
the fissures of eruption in Iceland. A glance at the satellite of our
planet will impart a wider generalization to this analogy of configuration.
by means of the charts that have been drawn in accordance with the
observations made with large telescopes, we may recognize in the moon, where
water and air are both absent, vast craters of elevation surrounding or
supporting conical mountains, thus affording incontrovertible evidence of
the effects produced by the reaction of the interior on the surface, favored
by the influence of a feebler force of gravitation.
Although vocanoes are justy termed in many languages "fire-emitting
mountains," mountains of this kind are not formed by the gradual
accumulation of ejected currents of lava, but their origin seems rather to
be a general consequence of the sudden elevation of soft masses of trachyte
or labradoritic augite.
Pages:
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482