The top half of this illustration shows men polishing glas in a glasworks while the bottom half depicts the equipment used for the proces. Plate or sheet glas was first produced in France in 1688, using a new proces whereby molten glas was poured onto a special surface, rolled flat and left to cool. This method allowed larger, better quality sheets to be produced. Illustration from 'Manufacture des Glaces', ('Glas Manufacture') by Denis Diderot (1713-1784), published in Paris in 1765, an excerpt from 'Encyclopedie, ou Dictionnaire Raisonne des Sciences, des Arts et des Metiers', edited by Diderot and Jean d'Alembert (1717-1783); in English, 'Grand Encyclopedie' (Encyclopedia or Dictionary of the Sciences, Arts and Profesions).
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