thunder.

2.
Aurora Borealis. The outer circle around the earth represents
atmosphere. The sun current carries it far from the earth's surface.
At the north, when the sun's reflection strikes the earth's crust in
such a manner, its reflection will be seen in the atmosphere at a
great height, called Northern Lights. This is mostly seen in
November, December, and January.


[Figure: Uncaptioned line drawing (accompanying the paragraph above)
of the Earth's orbit about the sun.]


3.
The museum of Alexandria was established about 400 years B.C., for the
purpose of restoring science that had been lost thousands of years
before.

The cultivation of knowledge by experiment, observation, and
mathematical discussions: this was the birth of a science of to-day.
The library contained many thousands of volumes of books, but was
destroyed by Cyril; a girl in charge of the library by the name of
Hypatia was brutally killed and the flesh was scraped from her bones
with sea shells. This occurred in 414 A.D.

Alexander died at Babylon 323 B.C.

China, Mesopotamia, and India had made astronomical observations at