Sandy Castle, age 7, of Grant, Alabama, for her question:

How do they make glass:

Making glass is a special sort of baking, not the sort of baking you do in the kitchen. The ingredients are rocky minerals, chemicals and sometimes traces of metals. The heat of the furnace must be hotter than hot. There are thousands of recipes for making different types of glass. But always the ingredients must be melted together in a fantastically hot furnace. The simplest kind of glass is made from sand, soda and lime    and the furnace melts these ingredients together.

When the mixture is melted, it is a tacky substance somewhat like moldable plastic. It is too hot to be touched by human hands. But it must be worked and shaped because as it cools it sets hard. It may be squeezed through mighty rollers and pressed into flat sheets. It may be pressed and shaped in molds. Or machines may blow air into the warm pliable glass to make hollow bottles.