Portable Sundials
Commentary
Diptych Dial, by a Tucher Workshop, Nuremberg, c. 1600
Details. Materials: Ivory, gilt brass, silver and glass. Dimensions: Height 119 mm, Width 94 mm, Depth 16 mm. Copyright: Museum of the History of Science, University of Oxford, Inventory No. 41986. Further detail: Epact entry: 78782
Commentary. The magnetic compass allowed the creation of portable sundials which could be easily orientated to face south. Nuremberg emerged as the principal centre in Europe for the development of such useful and prestigious instruments, the solar pocket watches of their time. One variety, like this one, was made of ivory. The features and functions of this particular dial are explained by a three-minute video created by the MHS. A second animated video below explains further how this kind of dial was used.
Other examples. Dialing was central to the interests of the founder of the Museum of the History of Science, Lewis Evans, who holds this very dial in the portrait which now hangs in the Museum. Sundials loom large within the hundreds of items contained in the Lewis Evans Collection; and dozens of further diptych dials are described in the Epact handlist (items 193 to 248). One of these is discussed in the MHS virtual exhibition on The Renaissance in Astronomy (items 12 and 26). Even more complex portable dials are the astronomical compendia (Epact handlist numbers 107 to 142).
Literature: P. Gouk, The Ivory Sundials of Nuremberg 1500-1700 (Cambridge, 1988), a book devoted principally to the collection of ivory sundials in the MHS; Steven A. Lloyd, Ivory Diptych Sundials 1570-1750 (Cambridge, Mass.,1992); Hester Higton, A Dial from his Poke: A History of Portable Sundials (London, 2000).
Credits: Howard Hotson (December 2017)