George Ravenscroft
George Ravenscroft was born in 1618 into a family that must have been reasonably affluent, since records refer to the male members of the family as “Gentleman” or “Esquire”. He was not a glassmaker and had reached the age of 55 before he set up a glass-house at the Savoy in London to carry out experiments to find a new form of glass.
He began this in 1673 and applied for a patent, first of all for “a particular sort of Christalline Glass”. He encountered serious faults in his wares, and his first task was to eliminate accidental tints in the production of a white glass. He then had to overcome what was known as “crizzling” or clouding of the transparency of the glass.
Ravenscroft finally decided that he had to make a stronger and more durable ware and, with these objects in mind, The Glass Sellers’ Company joined forces with him and supported him in the building of a second glass-house at Bell Street in Henley on Thames in 1674 so that he could pursue his researches in seclusion.
He had taken the precaution of obtaining a seven-year Patent on his new ideas, and by 1676 he had made such progress that the Company issued a certificate expressing their satisfaction with his “glass of flint”.
Originally, he had agreed to send the Company the whole of his output and the Company found it necessary to protect their monopoly by permitting Ravenscroft to use the raven’s head from his own bearings as a “Mark” or “Seal”, and glasses so marked were sold by the Company until his death in 1681.
Ravenscroft terminated his agreement with The Glass Sellers’ Company in 1679, but his work at the glass-house continued by his colleague Hawley Bishopp until 1685. As a result, his method of gradually adding lead oxide in the manufacturing of the glass became used in all glass making centres of England in the making of lead crystal, and put England at the head of the World market.
J. G. Thorpe. 2016
