This highly educational site from the department of paleontology at the National Museum of Natural History not only showcases beautiful examples of drawings and paintings of all things paleo, but it also includes wonderful explanations of the history and process of the art itself. As the site explains, paleontological art has been a key tool for dissemination of the institution’s findings since its inception in 1846. On the site, select Historical Art to view a variety of drawings and paintings from the 19th and early 20th centuries. A short, informative essay accompanies each work. Also have a look at Illustration Care and Illustration Techniques for pages of explanations about how the drawings are done, and then how they are cared for over time.