Christophe Fratin art links 

Art Institute of Chicago

Louvre Museum Database, Paris

Christophe Fratin at the National Gallery of Art, Washington D.C.
Cow Lowing over a Fence

Cleveland Museum of Art, Ohio

Courtauld Institute of Art, London, UK
2 works by or related to the artist

Indiana University Art Museum, Bloomington
Tiger Attacking a Young Camel, 1845

Indiana University Art Museum, Bloomington
Lion Carrying an Antelope, ca.1835-40

Maryland State Archives

National Museum of Wildlife Art, Jackson Hole, Wyoming

 
National Art Databases and Museum Inventories:

Smithsonian Institution Art Inventories
List of works nationwide from two sources: the Inventory of American Paintings Executed before 1914 and the Inventory of American Sculpture (only a few percent of listings have an accompanying image)

 

Peter Nahum At The Leicester Galleries, London, UK
Archive of past displayed works which are "sold" or "not for sale"

 

Union List of Artist Names (Getty Museum)  
Reference sheet with basic information about the artist and pointers to other references.