Original Audubon Imperial Quadruped. Very good condition as show. 21 x 28 inches. This incredibly detailed work is officially termedThe Viviparous Quadrupeds of North America. These mammals of North America were published in three volumes, dating 1845, 1846, and 1848. Somewhat more that 303 Imperial sets were printed and are rare and very valuable today. Besides the size, these prints are identified by the legend at the lower right "Lith. Printed & Cold. by J.T. Bowen, Phila."