Archaeological findings have proved that glassmaking was known to man more than 5,000 years ago. The transparent, hard but breakable substance we call glass be¬comes soft when heated carefully and can be blown, pressed, rolled and worked into different shapes. For hundreds of years, working with glass by blowing has been used for making beautiful and useful shapes of glass.
To blow glass in the traditional way, the glassblower takes a ball of molten glass, puts it at the end of his blow-pipe. When he skillfully blows through the blow-pipe the hot ball of glass could be blown like a balloon. The workable glass can be drawn out to required thinness and into different shapes. The glass has to be kept hot and workable by heating and reheating it. This method is called "freehand" glass blowing and is still used for making special and expensive glass articles.
I For making common glass articles such as bottles, in large numbers, machines are now used.