It will be carried about in the currents of air.
With what is the car attached to the balloon loaded?
It is usually loaded with bags of sand, which serve as a weight to keep it from rising too high.
When those in the car wish to go higher, what do they do?
They throw the sand out, so as to lighten the car; then it will rise higher.
When they wish to descend, what do they do?
They open a valve at the top of the balloon, which permits some of the gas to escape; then it will sink towards the earth.
How is the valve at the top of the balloon opened and closed?
It is opened and closed by means of small ropes, reaching from the valve to the car beneath.
Can the balloon be made to go in any one direction?