You have seen a small whirlwind in the street. The leaves flew round and
round, the dust whirled along in clouds. Trees are sometimes torn from
the ground, and houses overturned, by a strong wind.

Now think of a wind-storm in the desert. A loud, rustling noise is
heard. Great clouds of fine sand are lifted into the air--clouds which
darken the sun! Travelers must at once jump from their camels, cover
themselves with their cloaks, and lie flat on the ground.

The poor beasts will close their eyes and nostrils, and kneel with their
backs to the wind until the storm has passed over.

Thankful will the travelers be if none of them are buried in the sand.




LESSON XII.

HILLS, MOUNTAINS, VALLEYS.

The land is not always level like a plain. In some places it is high and
uneven. We all know what a _hill_ is. It is land a little higher than
the surrounding country.

Is there a hill near where you live? Let us walk to the _top_, and stand
on its _summit_. We will start from the _foot_ or _base_ of the hill.
Now we have climbed its steep, rough _sides_ or _slopes_. Was the ascent
difficult? Is the view from the top fine?