"In winter the temperature goes on increasing with the height, up to a certain limit, which is variable, according to the different atmospheric circumstances, the influence of which is not yet very exactly known. The hour of the day appears to be indifferent, since there exists no thermometric diurnal variation in the strata of the surface. The mean of thirty-six experiments, made with kites, or with captive balloons, at Bosekop, latitude 69 deg. 58' north, has given a mean rate of increase of 1 deg. 6' for the first hundred meters.[6] Beyond this limit, and even beyond the first 60 or 80 meters, the temperature again becomes decreasing, at first very slowly, but afterward the decrease is accelerated. The observations that have been made on the flanks, or on the summits, of mountains, during the same expeditions, entirely confirm these results. The cooling influence of a soil, that radiates its own heat for several weeks, without receiving any thing on the part of the sun, in compensation of its losses, the influence of _counter-currents from above_, coming from the west and the south-west, with a high temperature, account for this anomaly, which, in winter, represents the normal state of the most northern parts of the European continent." (Walker's Kaemtz, p. 515.--Note.) Mr. Walker is the only author, so far as I know, who has suspected the true cause of the phenomenon, viz.: "currents from above coming from the west and south-west, with a high temperature;" but the caloric theory "sticks like a burr," and he adheres also to the idea that a snow-clad surface, in the absence of the sun, can aid, by radiation, in warming the atmosphere for a distance of several hundred yards above it, increasing the warmth as the distance from the earth increases!