The sea and its living wonders; a popular account of the marvels of the deep / [G. Hartwig].

  • Hartwig, G. (Georg), 1813-1880
Date:
1866
Catalogue details

Licence: Public Domain Mark

Credit: The sea and its living wonders; a popular account of the marvels of the deep / [G. Hartwig]. Source: Wellcome Collection.

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    the water, and upon reaching the bottom, the strain upon the line ceases and the arms fall down, allowing the ball to detach itself entirely from the rod, which is then easily drawn up, and the drilled portion of which is discovered to be filled with a specimen of that which it has come in contact with at the bot- tom. Thus by this simple apparatus, the ocean bed may become in time as well known to us, as the bed of the Mersey or the Thames. The depths of the Pacific have as yet been very imperfectly explored; but soundings in the Atlantic have been so multiplied as to enable the celebrated hydrographer Maury, to draw a map which gives us at least a good general idea of the vales and mountain-chains, the shoals and abysses of yon great sea bed. Between Sierra Leone and Cape San Roque, the valley of the Atlantic deepens in mid-ocean to 21,450 feet, gradually shelving up towards both continents. Proceeding northwards, the pro- found submarine vale divides in the latitude of the West Indies into two arms, one of which runs parallel with the African and European coasts, whilst the other advances towards the great Bank of Newfoundland. To the south of this vast submarine •plateau the precipice is uncommonly steep, so that at the distance of a few leagues the sea deepens to 18,000 feet. What a spectacle would these prodigious mountain-walls afford, if we could wander about in the depths of the sea as easily as in some Alpine valley, and if our eye could pierce with the same facility the translucid waters, as it does the transparent regions of the atmospheric ocean ! The deepest depression of the Atlantic basin seems to lie between 33° and 40° N. lat., where the plummet has been lowered to the depth of 30,000 and even 40,000 feet; but naval surveyors are of opinion that the results may have been more or less deceptive, in consequence of a deflection of the line from the perpendicular by the drifting of the ship or strong submarine currents. At short distances from Madeira, the Cape de Verd Islands, and the Bermudas, the sea deepens to 12,000 and 15,000 feet, so that, seen from the ocean-ground, yon isle-clusters would appear as the summits of mighty mountain lands, grand and imposing as the Andes. Towards the north the bed of the Atlantic rises and forms,