y Paper, and Glass Transformed 195 



times as strong as ordinary plate glass. A pane of this glass, 

 resting on a cake of ice, will withstand a stream of molten 

 lead. A two-pound ball can drop six feet on this glass and not 

 even scratch it. This glass, and Vycor, will have many post- 

 war uses for windows in oven doors, tops of frozen-food cabi- 

 nets, strong tabletops, locomotive headlights, and revolving 

 doors. And it is quite possible that your postwar home will 

 have entire walls of this transparent insulating glass that keeps 

 heat in during winter and excludes it in summer. 



There are several types of glass that you won't be able to 

 recognize as such. First we have "Foamglas," which was de- 

 veloped by Corning and Pittsburgh Plate Glass. This mate- 

 rial, which insists on being called glass, can be sawed and 

 drilled and will float like cork. The glass is made by adding 

 pure carbon to the batch. When it is heated the carbon com- 

 bines to form a gas, which puffs up the molten glass into a 

 mass of bubbles. This foamy glass is annealed to prevent later 

 cracking, and then is cut into slabs. A cubic foot of Foamglas 

 has more than five million bubbles, or air cells, and weighs 

 only ten to eleven pounds, while ordinary glass weighs one 

 hundred and fifty to one hundred and seventy-five pounds 

 per cubic foot. 



The air cells in Foamglas make it almost as buoyant as cork 

 or balsa wood and it is well suited for lifesavers, life rafts, and 

 pontoon-bridge floats. At the same time Foamglas is strong 

 enough to build walls or ceilings without special support. It 

 won't rot or burn and is verminproof. Any termite foolish 

 enough to tackle Foamglas will get a broken jaw for its 

 trouble. 



Foamglas is good news for the food and storage industries. 

 Tt will insulate cold-storage plants, ice-cream factories and 

 dairies, and also can be used in ovens and furnaces. 



Next in line comes Fiberglas, which is used for insulation 

 and to make attractive, flameproof draperies. In addition, 



