tag:blogger.com,1999:blog-3448259307836351996.post7197036345597994581..comments2024-01-06T10:38:37.486-05:00Comments on Conciatore: Glass or Rock?Paul Englehttp://www.blogger.com/profile/12112332768470669999noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-3448259307836351996.post-69910521193201122082016-02-25T08:47:34.099-05:002016-02-25T08:47:34.099-05:00While there is still debate and quite a bit of unc...While there is still debate and quite a bit of uncertainty, a consensus is forming that the first spectacles were rock crystal and less expensive glass versions came laterPaul Englehttps://www.blogger.com/profile/12112332768470669999noreply@blogger.comtag:blogger.com,1999:blog-3448259307836351996.post-70200007627451673382016-02-25T08:35:48.926-05:002016-02-25T08:35:48.926-05:00Early spectacle lenses were often made of natural ...Early spectacle lenses were often made of natural rock crystal rather than glass, which was frequently clearer than the poor quality optical glass made in the 13th and 14th centuries. Interestingly when Lipperhey the inventor of the telescope applied for a patent in 1608 he was denied his patent but got a commission to produce three pairs of binoculars. One stipulation of the commission was that the lenses should be made of rock crystal and not glass.Anonymousnoreply@blogger.com