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Bull-Doser - Public Domain
Angela Sykes -
Silas Farmer - Public Domain
unknown - Public Domain
Lucas Vorsterman (II)Pieter Meert - Public Domain
Prolineserver -
John Kay - Public Domain
Markyrowland - CC BY-SA 3.0
Francis Grant - Public Domain
Scooge - CC BY 3.0
Auguste Edouart - 1842 - Public Domain
Notman Photo Co., Boston (late 19th century) - Public Domain
Dicklyon - CC BY-SA 4.0
Unattributed - Public Domain
Public Domain
Dr. A. E. ("Ted") Hill - CC BY-SA 3.0
Not credited - Public Domain
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Bull-Doser - Public Domain
Gauthier, Éric 1975-
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Dickstein, S. (Samuel), 1851-1939
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Mason, James, 1909-1984
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Angela Sykes -
Blacker, Terence
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Silas Farmer - Public Domain
Ledyard, Henry, 1812-1880
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unknown - Public Domain
Conway, Moncure Daniel, 1832-1907
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unknown - Public Domain
Harron, Robert, 1894-1920
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Lucas Vorsterman (II)Pieter Meert - Public Domain
Bie, Adriaen De
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Hunt, Leavitt
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Prolineserver -
Slichter, Charles P.
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Comstock, Daniel F. (Daniel Frost), 1883-1970
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Scott, Zachary, 1914-1965
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John Kay - Public Domain
Jamieson, John, 1759-1838
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Markyrowland - CC BY-SA 3.0
Daley, 1989-
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Francis Grant - Public Domain
Campbell, John Campbell, Baron, 1779-1861
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unknown - Public Domain
Ball, Joseph H. (Joseph Hurst), 1905-1993
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Townley, James, 1774-1833
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Scooge - CC BY 3.0
Stoner, Sherri
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Auguste Edouart - 1842 - Public Domain
Jones, Joel, 1795-1860
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Haymes, Dick
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Notman Photo Co., Boston (late 19th century) - Public Domain
Carpenter, George Rice, 1863-1909
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Roos, Joanna, 1901-1989
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Dicklyon - CC BY-SA 4.0
Shima, Masatoshi
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Unattributed - Public Domain
Maréchal, Maurice, 1892-1964
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Public Domain
Spilhaus, Athelstan
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Dr. A. E. ("Ted") Hill - CC BY-SA 3.0
Snow, Barbara K.
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Smythe, Reggie
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Roebling, Washington Augustus, 1837-1926
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Bazaine, François-Achille, 1811-1888
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Not credited - Public Domain
Lucas, Anthony F. (Anthony Francis), 1855-1921