regions has been accompanied by its diminution in the eastern parts of Asia, as Baron Von Wrangel was assured by the natives there, who added, that formerly it was brighter than at present, and frequently presented the vivid coloring of the rainbow. [Illustration: Halos.] The simplest form of the halo is that of a white concentric ring surrounding the sun or moon, a very common appearance in our climate in relation to the moon, occasioned by very thin vapor, or minute particles of ice and snow, diffused through the atmosphere deflecting the rays of light. Double rings are occasionally seen, displaying the brightest hues of the rainbow. The colored ring is produced by globules of visible vapor, the resulting halo exhibiting a character of density, and appearing contiguous to the luminous body, according as the atmosphere is surcharged with humidity. Hence a dense halo close to the moon is universally and justly regarded as an indication of coming rain. It has been stated as an approximation, that the globules which occasion the appearance of colored circles, vary from the 5000th to the 50,000th part of an inch in diameter. Though seldom apparent around the sun in our climate, yet it is only necessary to remove that glare of light which makes delicate colors appear white, to perceive segments of beautifully tinted halos on most days when light fleecy clouds are present. The illustration shows a nearly complete and slightly eliptical ring around the sun, the lower portion hidden by the horizon, which was distinctly observed during the past summer in the neighborhood of Ipswich, of an extremely pale pink and blue tint. When Humboldt was at Cumana, a large double halo around the moon fixed the attention of the inhabitants, who considered it as the presage of a violent earthquake. The hygrometer denoted great humidity, yet the vapors appeared so perfectly in solution, or rather so elastic and uniformly disseminated, that they did not alter the transparency of the atmosphere. The moon arose after a storm of rain behind the Castle of St. Antonio. As soon as she appeared on the horizon, two circles were distinguished, one large and whitish, 44° in diameter, the other smaller, displaying all the colors of the rainbow. The space between the two circles was of the deepest azure. At the altitude of 4° they disappeared, while the meteorological instruments indicated not the slightest change in the lower regions of the air. The phenomenon was chiefly remarkable for the great brilliancy of its colors, and for the circumstance that, according to the measures taken with Ramsden’s sextant, the lunar disc was not exactly in the centre of the halos. Humboldt mentions likewise having seen at Mexico, in extremely fine weather, large bands spread along the vault of the sky, converging toward the lunar disc, displaying beautiful prismatic colors; and he remarks, that within the torrid zone, similar appearances