Lord Rosse's great 72-inch (1.828m) diameter reflecting telescope of 1845, called the Leviathan of Parsonstown.  Mounted between two brick walls, it could move only in a north-south direction.  The Earth's rotation provided movement in an east-west direction.  Engraving from 'A Handbook of Descriptive Astronomy' by George F Chambers (Oxford, 1890).  William Parsons, 3rd Earl of Rosse (1800-1867).
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