In 1673 the merchant and entrepreneur George Ravenscroft opened the Savoy Glasshouse on the Strand in London, taking out a seven-year patent to produce, in his own words, a ‘perticuler sort of Christaline Glasse resembling rock Christall’. In order to counter the cloudy, crizzling effect of his early glass, Ravenscroft began adding lead oxide to his formula, effectively creating a new material and transforming the British glass industry with his vastly improved type of ‘metal’. The heavy and slow-cooling lead glass admirably suited a simple but elegant style and achieved a glass body of great clarity, with a high refractive index and distinctive appearance.