The circulation of the waters on the surface of the earth / by H.W. Dove.

  • Dove, Heinrich Wilhelm, 1803-1879.
Date:
1871
Catalogue details

Licence: Public Domain Mark

Credit: The circulation of the waters on the surface of the earth / by H.W. Dove. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    E live on the boundaries between two oceans; above the liquid expanse of the watery main, and at the bottom of the blue deeps of air. It is impossible for us to reach the sur- face of the latter, for our highest mountains pierce but its shallows, the azure waves rolling far over their summits. Of the former, only the surface is known to us; the secrets of its depths are hidden from our ken. Thus the greatest part of the firm crust of the earth is withdrawn from our investi- gation. Mighty masses of earth, it is true, rise up out of the ocean, making the proportion of the firm bottom of the sea of air to the liquid one as 51 to 146. But the idea that, could we succeed in draining the ocean dry, those masses that tower over the level of the ocean would serve to fill up the gaps, is long- ago renounced as beiug incorrect. Humboldt fixed the mean height of the continents at about a thousand feet above the level of the ocean. While Bache calculated the mean depth of the Pacific at 14,190 feet, from the time needed by the wave of the earthquake (Dec. 23. 1859, when the Russian frigate Diana was lost), which rose thirty feet above the usual level, in the harbour of Simoda in Japan, to cross the Pacific to San Francisco and San Diego in California — rate = 6,i league per minute, by 217 miles breadth of wave. Still this ratio is greatly exceeded in the deepest places; for Ross at a southern latitude of 15° 3', and a western longitude of 23° 14', found no bottom at a depth of 27,000 feet. Denham in the Her-