The books on display here, all from the collections of Gould Library, reveal the beauty and order of hidden worlds. In these volumes, microscopic images are deployed for a variety of reasons: Sometimes their purpose is purely practical (to certify the purity of a sample of tea, or to facilitate the identification of diseased blood). In other cases, as in Felice Frankel’s close-up view of Velcro, their job is as much to inspire curiosity and wonder as it is to illustrate a scientific phenomena.