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Seeing the Universe

before 1610 - naked eye astronomy
1608 - Galileo's hand held telescopes
1673 - Hevelius' long telescopes
1780 - Herschel's large reflectors
1838 - Meridian Circles
1845 - Rosse's Leviathian
1890 - Barnard's camera
1923 - The Hooker 100 inch
1948 - The Palomar 200 inch
1990 - The Hubble Space Telescope
1998 - The Keck 10 metre pair
2000 - The VLT array
2015 - Planning for the JWST
2020? - Planning the OWL
How much further?

In 1781 William Herschel discovered the planet Uranus. He also discoverd moons around Saturn and Uranus, realised that spectrum of star light extended beyond the visble into the infrared, mapped thousands of nebulae, and deduced the structure of the Milky Way. In his quest for better views of the universe, he built a series of reflecting telescopes. The image shows the largest, with a 48 inch mirror, constructed in 1786. It prooved difficult to use. The observer, standing on the platform, peering into the body of the instrument, steered it onto targets by calling out instructions to a team of workmen. They pushed the structure around its track and hauled on ropes, running through a pulley system, to raise or lower the tube. Herschel returned to doing most of his work on an earlier, more manageable, 24 inch reflector.  The Herschel Museum

Herschel's 48 inch reflecting telescope (Herschel Museum)