Portable Diptych Sundial by T. G. Kleininger

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Description
This rectangular wooden diptych sundial has paper scales and tables with black ink and green and red coloring. A brass hook and eye hold the sundial open for use; a hook for keeping the dial closed is missing. Leaf 1a is a latitude table for 36 European and American cities (a complete list is in the accession file). Leaf 1b contains holes for latitudes of 40, 42, 44, 46, 48, 50, 52, 54, and 56 degrees, although only the holes 46-52 are drilled completely through the leaf and therefore functional. A string gnomon is tied loosely at 46 degrees. Leaf 1b also contains an equinoctial sundial calibrated from VII to XII to V by units with lines at the half-hour points. Leaf 2a contains a horizontal sundial calibrated from 4 to 12 to 8 by units with divisions for each fifteen-minute interval. Inset in the inside of this face is compass with a rose of four labeled cardinal points. The compass is offset roughly ten degrees west for magnetic variation. The compass glass and needle are missing. Leaves 1b and 2a are decorated with flowers and garlands of leaves.
T. G. Kleininger made diptych and cube dials in Germany and/or the Netherlands. His initials are reported variously as J. G. (Adler Planetarium), I. G. (National Maritime Museum, Greenwich; Whipple Museum), and J. P. (Museum of the History of Science, Oxford). The latitude table and compass directions on this dial mix German, French, and English terms (for example: Nord, Ost, Sud, West). Also notable is that Washington, D.C., is listed even though Kleininger is only known to have been active in the second half of the 1700s. Perhaps this indicates that the dial dates to the 1790s.
References:
Museum of the History of Science, Oxford website, inventory number 20302 (accessed 12 September 2002).
The Whipple Museum of the History of Science, Catalogue 6: Sundials and Related Instruments, Part 2, Object 170
Online Register of Scientific Instruments, (accessed 12 September 2002).
Location
Currently not on view
subject
Mathematics
Timekeeping
National Museum of American History
Kleininger, T. G.
Measurements
overall: 1.5 cm x 4.5 cm x 8 cm; 19/32 in x 1 25/32 in x 3 5/32 in
See more items in
Medicine and Science: Mathematics
Science & Mathematics
1790s?
Object Name
sundial, horizontal portable
sundial
ID Number
MA.330853
catalog number
330853
accession number
1987.0706