Page 40 - Curriculum Visions Dynamic Book

Cylinder glass
An alternative that produced larger glass pieces, for example, for mirrors, was not to spin the bubble but to allow a giant cylinder to cool slightly, then cut it lengthwise. As it was reheated, the cylinder of glass spread out into a sheet.
(Below) The Great Exhibition of 1851 in London was held in the Crystal Palace. It required 300,000 panes of glass. All were made by the cylinder process. The construction used a third of England’s entire glass production for a year. However, following this exhibition, people’s views of how glass could be used changed forever.
(Below) Early forms of making
flat glass began by producing huge cylinders of glass that were laid
flat, cut open, and reheated so they changed into sheets. Despite all of this effort, the quality of the glass was not high, and irregularities in the thickness led to many distortions.
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