f a day at the Equator by von Spix and v. Martius in
their Travels in Brazil in 1817 to 1820:

In these seas the sun rises from the ocean with great splendour,
and gilds the clouds accumulated in the horizon, which in grand
and various groups seem to present to the eye of the spectator
continents with high mountains and valleys, with volcanoes and
seas, mythological and other strange creations of fancy.

The lamp of day gradually rises in the transparent blue sky; the
damp grey fogs subside; the sea is calm or gently rises and
falls, with a surface smooth as a mirror, in a regular motion. At
noon a pale, faintly shining cloud rises, the herald of a sudden
tempest, which at once disturbs the tranquillity of the sea.
Thunder and lightning seem as if they would split our planet; but
a heavy rain of a salt taste, pouring down in the midst of
roaring whirlwinds, puts an end to the raging of the elements,
and several semi-circular rainbows, extended over the ocean like
gay triumphal arches, announce the peaceful termination of the
great natural phenomenon. As soon as the air and sea have
recovered their equilibrium, the sky again shews its transparent
azure.... As the sun gradually sinks in the clouded horizon, the
sea and sky assume a new dress, which is beyond description
sublime and magnificent. The most brilliant red, yellow, violet,
in infinite shades and contrasts, are poured out in profusion
over the azure of the firmament, and are reflected in still gayer
variety from the surface of the water. The day departs amid
continued lightning on the dusky horizon, while the moon in
silent majesty rises from the unbounded ocean into the cloudless
upper regions. Variable winds cool the atmosphere; numerous
falling stars, coming particularly from the south, shed a magic
light; the dark-blue firmament, reflected with the constellations
on the untroubled bosom of the water, represents the image of the
wholly starry hemisphere; and the ocean, agitated even by the
faintest breeze of the night, is changed into a sea of waving
fire.... The variety of the light and foliage of the trees, which
is seen in the forests, on the slopes of the mountains: the
blending of the most diverse colours, and the dark azure and
transparency of the sky, impart to the landscapes of the tropical
countries a charm