New York: V.G. Audubon, Roe Lockwood & Son, 1860. 7 volumes, octavo. (10 1/2 x 6 1/2 inches). 500 hand-coloured lithographs. Contemporary half brown morocco and marbled paper boards The fourth octavo edition of Audubon's "Birds": an important American color plate book and one of the most desirable books produced in 19th-century America. The octavo editions of Audubon's The Birds of America are certainly the most famous and accessible of American color plate books. They served many purposes for Audubon. First, the octavo edition was a moneymaker, successfully marketed throughout the United States on a scale that the great cost of the original Birds made impossible. Second, it was another step toward proving himself as good a scientific naturalist as the "closet" naturalists who had scorned him, combining a detailed text with careful observations next to his plates. Third, the smaller format allowed a more reasonable arrangement, by genus and species, than the headlong production…