In northern latitudes the effects of atmospheric reflection and refraction are very familiar to the natives. By the term of _uphillanger_ the Icelanders denote the elevation of distant objects, which is regarded as a presage of fine weather. Not only is there an increase in the vertical dimensions of the objects affected, so that low coasts frequently assume a bold and precipitous outline, the objects sunk below the horizon are brought into view, with their natural position changed and distorted. In 1818, Captain Scoresby relates that, when in the polar sea, his ship had been separated for some time from that of his father, which he had been looking out for with great anxiety. At length, one evening, to his astonishment, he beheld the vessel suspended in the air in an inverted position, with the most distinct and perfect representation. Sailing in the direction of this visionary appearance, he met with the real ship by this indication. It was found that the vessel had been thirty miles distant, and seventeen beyond the horizon, when her spectrum was thus elevated into the air by this extraordinary refraction. Sometimes two images of a vessel are seen, the one erect and the other inverted, with their topmasts or their hulls meeting, according as the inverted image is above or below the other. Dr. Wollaston has shown that the production of these images is owing to the refraction of the rays through media of different densities. Looking along a red-hot poker at a distant object, two images of it were seen, one erect and the other inverted, arising from the change produced by the heat in the density of the air. A singular instance of lateral mirage was noticed upon the Lake of Geneva by MM. Jurine and Soret, in the year 1818. A bark near Bellerire was seen approaching to the city by the left bank of the lake; and at the same time an image of the sails was observed above the water, which, instead of following the direction of the bark, separated from it, and appeared approaching by the _right_ bank—the image moving from east to west, and the bark from north to south. When the image separated from the vessel, it was of the same dimensions as the bark; but it diminished as it receded from it, so as to be reduced to one-half when the appearance ceased. This was a striking example of refraction, operating in a lateral as well as a vertical direction.