Yes; loaded cars, and even heavy buildings, may be raised by means of a screw of this kind.

CHAPTER XI.
Electricity.

When a cat’s back is rubbed in the dark, what does it give off?

It gives off small sparks.

What are these small sparks called?

They are called electric sparks, or electricity.

If a horse be rubbed in the winter when it is dark, what will be given off from him?