When have we hail?
When the rain-drops, while falling, pass through a current of air cold enough to freeze them, hail is produced.
Ice.
What is ice?
Ice is frozen water.
When does water freeze?
Water freezes when its temperature is reduced to thirty-two degrees.
Is water increased in bulk by freezing?
Water is increased in bulk by freezing.
Why do water-pipes often burst in cold weather?