Since daybreak large clouds obscured the horizon.

Already a storm was threatened in the air.

Probably the day would not end without some thunder-claps.

Happily the forest, more or less dense, retained a little freshness of the surface of the soil.
Here and there great forest trees inclosed prairies covered with a tall, thick grass.

In certain spots enormous trunks, already petrified, lay on the ground, indicating the presence of coal mines, which are frequently met with on the African continent.