The ocean world : being a descriptive history of the sea and its living inhabitants / Chiefly translated from "La vie et les moeurs des animaux".

  • Figuier, Louis, 1819-1894.
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: The ocean world : being a descriptive history of the sea and its living inhabitants / Chiefly translated from "La vie et les moeurs des animaux". Source: Wellcome Collection.

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    these waters would submerge it to the depth of more than six hundred :feet. Again, admitting the mean depth of the sea to he thirteen thousand feet, its estimated contents ought to he nearly two thousand two hundred and fifty millions of cubic miles of water; and, if the sea could be imagined to he dried up, all the sewers of the earth would require to pour their waters into it for forty thousand years, in order to fill the vast basins anew. If we could imagine the entire globe to be divided into one thousand seven hundred and eighty-six parts by weight, we should find approxi- mately, according to Sir John Ilerschel, that the total weight of the oceanic waters is equivalent to one of these parts. The specific weight of sea water is a little above that of fresh water, the proportion being as a thousand to a thousand and twenty-seven. The Dead Sea, which receives no fresh water into its bosom to main- tain itself at the same level as other seas, acquires a higher degree of saltness, and is equal to a thousand and twenty-eight. The specific gravity of sea water is about the same as the milk of a healthy woman. The colour of the sea is continually varying. According to the testimony of the majority of observers, the ocean, seen by reflection, presents a fine azure blue or ultramarine (cseruleum mare). When the air is pure and the surface cahn this tint softens insensibly, until it is lost and blended with the blue of the heavens. Near the shore it becomes more of a green or glaucus, and more or less brilliant, according to circumstances. There are some days when the ocean assumes a livid aspect, and others when it becomes a very pure green; at other times, the green is sombre and sad. When the sea is agitated, the green takes a brownish hue. At sunset, the surface of the sea is illumined -with tints of every hue of purple and emerald. Placed in a vase, sea water appears perfectly transparent and colourless. According to Scoiesby, the Polar Seas are of brilliant ultramarine blue. Castaz says of the Mediterranean, that it is celestial blue, and Tuckey describes the equinoctial Atlantic as being of a vivid blue. Many local causes influence the colours of marine waters, and ^ive :hem certain decided and constant shades. A bottom of white sand tVlU communicate a greyish or apple-green colour to the water, if not