On August 3, in the very middle of the short Taimurian summer, in 74° 15´ of latitude, Middendorff hunted butterflies under the shelter of a hill, bare-footed and in light under-clothes. The thermometer rose in the sun to +68°, and close to the ground to +86°, while at a short distance on a spot exposed to the north-eastern air-current it fell at once to +27°. The moisture of the air was very remarkable. In May thick snow-fogs almost perpetually obscured the atmosphere, so that it was impossible to ascertain the position of the sun. It appeared only in the evening, or about midnight, and then regularly a perpendicular column of luminous whiteness descended from its orb to the earth, and, widening as it approached the horizon, took the form and the appearance of a colossal lamp-flame, such as the latter appears when seen through the mists of a vapor bath. From the same cause parhelia and halos were very frequent. During the daytime the snow-fogs, in perpetual motion, either entirely veiled the nearest objects, or magnified their size, or exhibited them in a dancing motion. In June the snow-fog became a vapor-fog, which daily from time to time precipitated its surplus of moisture in form of a light rain, but even then the nights, particularly after eleven o’clock, were mostly serene. Experience proved, contrary to Arago’s opinion, that thunder-storms take place within the Arctic zone. The perpetual motion of the air was very remarkable. The sun had merely to disappear behind a cloud to produce at once a gust of wind. Towards the end of August, the southern and the northern air-currents, like two contending giants, began to strive for the mastery, until finally the storms raged with extreme violence. But in these treeless deserts their fury finds nothing to destroy. It is impossible to form any thing like a correct estimate of the quantity of snow which annually falls in the highest latitudes. So much is certain that it can not be small, to judge by the violence and swelling of the rivers in spring. The summits of the hills, and the declivities exposed to the reigning winds, are constantly deprived of snow, which, however, fills up the bottom of the valleys to a considerable height. Great was Middendorff’s astonishment, while travelling over the tundra at the end of winter, to find it covered with no more than two inches, or at the very utmost half a foot, of snow; the dried stems of the Arctic plants everywhere peeping forth above its surface. This was the natural consequence of the north-easterly storms, which, sweeping over the naked plain, carry the snow along with them, and form the snow-waves, the compass of the northern nomads. It is extremely probable that, on advancing towards the pole, the fall of snow gradually diminishes, as in the Alps, where its quantity likewise decreases on ascending above a certain height.