Page:Polar Exploration - Bruce - 1911.djvu/234

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230
POLAR EXPLORATION

thing resembling an aurora, extremely faint, and uncertain if they had not been accompanied by magnetic perturbations. We had glares of pale green, which might have been attributed to auroras, but I really do not think they were. The two auroras showed themselves in the S.E." On the other hand, the English expedition in MacMurdo Sound had frequent displays during the whole time the Discovery wintered. "On the whole the displays, although very frequent, were extremely poor, and were generally in the following forms:" (1) Faint lights with no defined forms. (2) Luminous patches, which frequently presented the appearance of clouds. (3) Incomplete arcs, or segments of arcs, of which the brilliance was not uniform nor the border regular. From these arcs rays would frequently shoot up intermittently. (4) Rays, or vertical shafts, separated from each other at a greater or less distance, frequently described as streamers. (5) In one or two exceptional cases irregular bands, formed of rays or vertical shafts, pressed close together and forming "draped auroræ."

"The faint lines and luminous patches were of the most varied dimensions, sometimes very small and at other times occupying almost the whole of the eastern (geographical) sky; their brilliancy was rarely much more intense than that of stars of the 4th magni-