More history The following was added to the intro at Telescope I am moving it here because it seems to deal with specifically Optical telescopes I am putting it in talk because some of it does not have much to do with telescopes camera obscura pinhole lenses ect and it is full of un cited claims Crystal Balls were used in China and India as lenses possibly in the form of a camera obscura to see at a distance as early as 400 BCE Around 1000 CE the Arabian astronomer and mathematician Ibn al Haytham expanding and scientifically testing theories of Euclid Ptolomey and Aristotle wrote about both pinhole lenses and concave lenses in his mathematical book on vision Roger Bacon wrote about combining lenses to see at a distance in the 13th century as did the 16th Century Italian spectacle maker Giambattista della Porta 1538 1615 and a host of others