Atmosphere : a philosophical work / by George Woodhead.

  • Woodhead, George.
Date:
1852
Catalogue details

Licence: Public Domain Mark

Credit: Atmosphere : a philosophical work / by George Woodhead. Source: Wellcome Collection.

    22/164 (page 10)
    The summits of the lofty mountains within the tropics, which, while smitten by the sun's intensest rays, are wrapped in everlasting ice, attest that in those rays there is no heat. In the case of the ex- hausted receiver, the reason why the light does not produce its asual effect, obviously is the want of air. In the other case the reason is analogous, or the same—the want of sufficient air and atmospheric pressure, to assist the action of the Hght. Ascending from the earth's sm^face, the density and pressure of the atmosphere are known gradually to decrease;* and it admits of no doubt that the atmosphere about the summits of those mountains is too highly rarefied to enable the sun's light to act with effect. Those summits probably rise to, and perhaps transcend, the surface of the ocean of air which rests upon the earth, f * See the paper On Atmospherical Pressure, page 91. ■j-Baron Humboldt expresses a shnilar opinion respect-