At the Waterford Crystal Visitor Centre, you can learn how crystal is produced.
The glass blower gathers up a big blob of molten glass from the glass furnace with a hollow rod. He then takes the glass and rod and rests them on a wooden beam.
The rod must be kept moving so the glass does not form a big, molten blob and fall off. As he rolls it back and forth over the wooden beam, he shapes it with different metal instruments.
If he is making something that is hollow inside, he just puts his mouth on the rod and blows into the glass blob to make a big bubble. Some pieces of glass are "mold blown" meaning that the glass worker puts the blob into a mold and blows the bubble of glass to fill the mold.
After the glass is shaped the way the artist wants it, it is cut away from the rod and cooled.