5,500 illustrations from the 19th century include star maps, animals, plants, minerals, fossils, geological formations, human anatomy, and much more.
Here's a sample of other books in this Dover category
Animals: 1,419 Copyright-Free Illustrations of Mammals, Birds, Fish, Insects, etc. by Jim Harter Selected for its visual impact and ease of use, this outstanding collection of wood engravings presents over 1,000 species of animals in extremely lifelike poses. Includes mammals, birds, reptiles, amphibians, fish, insects, and other invertebrates.
Plants and Flowers: 1761 Illustrations for Artists and Designers by Alan E. Bessette, William K. Chapman One of the finest, most extensive sources of royalty-free illustrations of the world's plants and flowers, chosen for scientific accuracy, artistic style. Common and botanical Latin names specified. 1,761 black-and-white illustrations.