Plate or Sheet Glass

Image: Manufacture of Rolled Plate Glass.  Chance Brothers & Co., Limited, 100 Years of British Glass Making 1824-1924 (Smethwick and Glasgow, Chance Brothers & Co., 1924).

Image from: Local Studies and History, Birmingham Central Library

Blowing the “metal” into the form of a cylinder was the first stage of making sheet glass. J F Chance detailed the modes of production in his book. The workman judged the dimensions and thickness of the walls of these cylinders with a skill that could only be acquired after years of practice.  The perfectly formed cylinder was then cut longitudinally and reheated in a flattening kiln or “lear” where it gradually opened out into a flat sheet, limited in size and thickness only by the weight of the glass that the blower could wield. The advantage over crown glass was that greater dimensions could be achieved in one single pane of glass, therefore, avoiding wastage. The disadvantage of this glass was an unevenness of surface and a comparative lack of brilliance. These shortcomings were soon resolved by the invention of grinding and polishing machines by James Timmins Chance.