Book 41

Gravity Is A Mystery

by Franklyn M Branley

Published 23 September 1971



Explains how and why a thunderstorm occurs and gives safety steps to follow when lightning is flashing.

The Sun

by Franklyn M Branley

Published December 1963


Introduces the solar system and its nine planets. Includes directions for making two models: one showing relative sizes of the planets and the other, their relative distances from the sun.



Moon Seems to Change

by Franklyn M Branley

Published December 1962

Can you see the moon?

Does it look like a big round ball? Or is it just a sliver of light in the sky? The moon seems to change. But it doesn't really. The moon revolves around the Earth. It takes about four weeks to make the journey, and as it travels round we can only see certain parts of it. Try the simple experiment described inside using an orange, a pencil, and a flashlight, and you'll understand why the moon seems to change.