FIG. 2--TWO TYPES OF AURORAL RAYS.
(From the _Internationale Polarforschung_, 1882-1883, by permission
of the _Kaiserlichen Akademie der Wissenschaften_, Vienna.)]
[Illustration: PLATE II.
Encyclopaedia Britannica, 11th Edition, "Atherstone" to "Austria" Volume 2, Slice 8 · 第 37 / 58 题