“In a fine summer’s night, when the sky is loaded only with some light vapours, sufficient to stop and to refract the rays of the sun, walk out into an open plain, where the first fires of Aurora may be perceptible.  You will first observe the horizon whiten at the spot where she is to make her appearance; and this radiance, from its colour, has procured for it, in the French language, the name of aube, (the dawn,) from the Latin word alba, white.  This whiteness insensibly ascends in the heavens, assuming a tint of yellow some degrees above the horizon; the yellow as it rises passes into orange; and this shade of orange rises upward into the lively vermilion, which extends as far as the zenith.  From that point you will perceive in the heavens behind you the violet succeeding the vermilion, then the azure, after it the deep blue or indigo colour, and, last of all, the black, quite to the westward.

“Though this display of colours presents a multitude of intermediate shades, which rapidly succeed each other, yet at the moment the sun is going to exhibit his disk, the dazzling white is visible in the horizon, the pure yellow at an elevation of forty-five degrees; the fire color in the zenith; the pure blue forty-five degrees under it, toward the west; and in the very west the dark veil of night still lingering on the horizon.  I think I have remarked this progression between the tropics, where there is scarcely any horizontal refraction to make the light prematurely encroach on the darkness, as in our climates.

“Sometimes the trade-winds, from the north-east or south-east, blow there, card the clouds through each other, then sweep them to the west, crossing and recrossing them over one another, like the osiers interwoven in a transparent basket.  They throw over the sides of this chequered work the clouds which are not employed in the contexture, roll them up into enormous masses, as white as snow, draw them out along their extremities in the form of a crupper, and pile them upon each other, moulding them into the shape of mountains, caverns, and rocks; afterwards, as evening approaches, they grow somewhat calm, as if afraid of deranging their own workmanship.  When the sun sets behind this magnificent netting, a multitude of luminous rays are transmitted through the interstices, which produce such an effect, that the two sides of the lozenge illuminated by them have the appearance of being girt with gold, and the other two in the shade seem tinged with ruddy orange.  Four or five divergent streams of light, emanated from the setting sun up to the zenith, clothe with fringes of gold the undeterminate summits of this celestial barrier, and strike with the reflexes of their fires the pyramids of the collateral aerial mountains, which then appear to consist of silver and vermilion.  At this moment of the evening are perceptible, amidst their redoubled ridges, a multitude of valleys extending into infinity, and distinguishing themselves at their opening by some shade of flesh or of rose colour.