Ivory Diptych Sundials, 1570-1750

During the sixteenth and seventeenth centuries, ivory diptych dials became popular devices for determining the time by the sun during the day or by the moon at night. These elaborate portable sundials, which could be adjusted for use in different latitudes, incorporated various devices useful for merchants and others who traveled extensively in Europe. This catalogue illustrates in detail Harvard's collection of 82 ivory diptych sundials, one of the largest holdings of these instruments in the world. The collection encompasses a comprehensive array of styles and designs from Nuremberg, Paris, and Dieppe, the major centers of their production, as well as from other parts of Europe. Harvard University has been purchasing scientific instruments on a continuous basis for teaching and research since 1765. The Collection of Historical Scientific Instruments, which was established in 1949 to preserve this apparatus as a resource for teaching and research in the history of science and technology, has become one of the three largest university collections of its kind in the world. It comprises about 15,000 instruments from 1500 to the present and covers a broad range of scientific disciplines, including astronomy, navigation, horology, surveying, geology, calculating, physics, biology, medicine, psychology, electricity, and communication. Illustrated catalogues of other parts of the collection are anticipated in the near future.Lloyd, Steven is the author of 'Ivory Diptych Sundials, 1570-1750' with ISBN 9780674469778 and ISBN 0674469771.