Troughton's universal equatorial, 1817.
© Science Museum / Science & Society Picture Library
Print showing a view of 'Troughton's Universal Equatorial, an astronomical instrument. The engraving, taken from 'Rees Cyclopedia' published 1812-1820, shows a small telescope carried on an equatorial mounting. Built by the London instrument maker, Edward Troughton, it was intended as a measuring instrument. The portable instrument could be used in the field or housed in an observatory building.