The height of the appearances varies from one to two hundred miles; they sometimes appear within the region of the clouds, and very near to the earth.
Do the auroras appear at any particular seasons and times?
They appear more frequently in the winter than in the summer, and are only seen at night.
Do they also occur in the day-time?
The aurora is known to affect the magnetic needle and the telegraph; and as the effects upon these instruments are noticed by day as well as by night, there can be no doubt of the occurrence of the aurora at all hours. The intense light of the sun renders the auroral light invisible during the day.
Of what utility are the auroral appearances in the polar regions?
During the long polar night, when the sun is absent, the aurora appears with a magnificence unknown in other regions, and affords light sufficient for many of the ordinary outdoor employments.
Magnetism
Is there any connection between magnetism and electricity?
There is every reason to believe that magnetism and electricity are but modifications of one force.