Lord Rosse directing the conveyance of the Great Speculum to its position at the Base of the Tube, North Side

William Parson was an Anglo-Irishman whose fascination for astronomy and large structures led him to build a reflecting telescope of 72-inches aperture. Its site was Birr Castle, the family home near the village of Parsonstown in the center of Ireland. Observations with the telescope, dubbed the Leviathan of Parsonstown, began in February 1845. An early discovery was the spiral structure of the M51, a celestial object then considered a nebula but now known to be a galaxy. Rosse’s telescope remained the world’s largest until 1917 when the 100-inch reflector was established on Mount Wilson.
This lithograph shows Parson's telescope. The text at the bottom reads: “THE GREAT TELESCOPE / (of 52 feet focus, 6 feet clear opening of speculum) / ERECTED AT BIRR CASTLE IN IRELAND, BY THE EARL OF ROSSE, PRESIDENT OF THE ROYAL SOCIETY” and “On Stone by W. Bevan, from a drawing by Miss Henrietta M. Crompton” and “Printed by W. Monkhouse, York.” The image was probably made during the period 1849-1854 when William Parsons, the Third Earl of Rosse, served as president of the Royal Society of London.
Henrietta Matilda Crompton (1793-1881) was a wealthy and well-educated Englishwoman who is remembered largely for the sketches she made on tours around the British Isles. William Bevan (fl. 1842-1855) transferred Crompton’s sketch onto a lithographic stone. William Monkhouse was a printer in York who apparently specialized in scientific subjects.
Ref: Patrick Moore, The Astronomy of Birr Castle (London, 1971).
John Moore, “The Leviathan of Parsonstown,” History Ireland 9 (2001): 18-22.
Stephen Allen Letters and Papers of Henrietta Matilda Crompton and her Family: a List with Extracts; & The Art of Henrietta Matilda Crompton (North Yorkshire, 1994).
Currently not on view
Object Name
Physical Description
paper (overall material)
overall: 14 1/2 in x 19 1/2 in; 36.83 cm x 49.53 cm
overall: 14 3/4 in x 19 1/2 in; 37.465 cm x 49.53 cm
ID Number
catalog number
accession number
Prints from the Physical Sciences Collection
Science & Mathematics
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Medicine and Science: Physical Sciences
Prints from the Physical Sciences Collection
Data Source
National Museum of American History, Kenneth E. Behring Center

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