Cecil, Evelyn: A history of gardening in England (London: Quaritch, 1896)

THE EAGLE OR MIRROR POND, NEWSTEAD ABBEY.
So named from the clearness of the reflections, and from a brass eagle lectern containing the papers of the monastery having
been found there in the 18th century. The size of the pond is 212 feet long by 104 feet wide. There is a flight of stone steps
descending into the water at each corner. (See page 90.)