Before vacuum insulated glass windows, there was sheet glass

The sheet glass manufacturing process was difficult, dangerous and made lousy glass. Glass was drawn up s from a molten pool of glass on a steel line. The glass was lifted creating a thin line. As the glass cooled it became stiff and was then cut into ribbons. The ribbons were then processed through inline grinders.  The surface was never smooth as the surface was not uniform. Pits and seeds formed as oxygen bubbles formed. The Foucault process lasted many years. The last sheet plant in the US was in Jenette Pennsylvania and closed in the late 1970's. With the advent of new technologies new processes for better glass and windows lead to other inventions like insulated glass.