Northern Lights.

Manufacturer and Builder ?, 1890

Auroras are most frequently seen in the Arctic and northern temperate zones, rarely in the southern temperate zone, and hardly ever in the tropics. The places where they appear most frequently lie between the sixteenth and seventeenth degrees of north latitude. In the form of an oval, they include the geographical as well as the magnetic north pole, which is to be found on the penin. sula Boothia Felix, Iceland, the Kara Sea, northern Siberia, Behrtng Strait, Hudson Bay, Labrador, and Greenland. Northern lights have been seen as far down as 25° of north latitude. In full splendor, however, they may be seen only in the northern polar regions to 75° of latitude. Here nature displays them in ail their grandeur. When the sun has set, and the gray veil of twilight is cast over the earth, the northern horizon grows darker and dai ker. Soon there may be distinguished a s,gment of the sky more somber than its background; this is hemmed in by white concentric arcs of light. Colored rays shoot forth there, from all directions. They interlace and intertwine until they seem to be woven into one fluttering band of color. And anon it changes to a sea of fire! The rays leap upward far above the zenith, form there a flaming crown, and then sink back, to begin anew the wonderous play. The most beautiful descriptions and trustworthy observations we owe to Nordenskjöld and Ekama. All explanations which have been attempted as to the origin and cause of northern lights are based on analysis by the spectroscope, on the determination of the elevation, and on observations of the peculiar behavior of the magnetic needle.

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