The aurora exercises a remarkable influence on the magnetic needle, even in places where the display is not visible. Its vibrations seem to be slower or quicker according as the auroral light is quiescent or in motion, and the variations of the compass during the day show that the aurora is not peculiar to night. It has been ascertained by careful observations that the disturbances of the magnetic needle and the auroral displays were simultaneous at Toronto, in Canada, on thirteen days out of twenty-four, the remaining days having been clouded; and contemporaneous observations show that in these thirteen days there were also magnetic disturbances at Prague and Tasmania; so that the occurrence of auroral phenomena at Toronto on these occasions may be viewed as a local manifestation connected with magnetic effects, which, whatever may have been their origin, probably prevailed _on the same day over the whole surface of the globe_. Among the _atmospheric_ phenomena of the outer world we are justified in reckoning the Winds, which are remarkable for their variability. Their force is considerably diminished when they pass over a wide surface of ice; sometimes the ice seems even to beat back the breeze, and turn it in a contrary direction. The warm airs from the south grow cool as they sweep across the frozen expanse, and give up their moisture in the form of snow. In a region so bleak and chill it is not often that clouds are created, the atmospheric vapours being condensed into snow or hail without passing through any intermediate condition. Whirlwinds of frozen snow are formidable enemies to the seaman forced to traverse the ice on foot, or in a sledge drawn by Eskimo dogs. Dense showers lash and sting the unfortunate traveller’s face, penetrate his mouth and nostrils, freeze together his very eyelids, and almost blind him. His skin assumes a bluish tint, and burns as if scarred by the keen thongs of a knout. An optical illusion of frequent occurrence in the Polar Regions makes objects appear of dimensions much larger than they really possess. A fox assumes the proportions of a bear; low banks of ice are elevated into lofty mountains. The eye is fatigued by dwelling upon the horizon of lands which are never approached. Just as in the sandy deserts of the Sahara the distances of real objects are apparently diminished, so the Arctic explorer, misled by the aërial illusion, advances towards a goal which seems always near at hand, but is never attained.