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ring sundial

Date17th Century
Inventory Number7127
ClassificationSundial
Subject
    Maker S. H. W. fl. 17th century
    Cultural Region
      Dimensions5.9 x 1.1 x 5.4 cm (2 5/16 x 7/16 x 2 1/8 in.)
      Material
        DescriptionThis brass ring dial has two pin holes in a sliding circular ring that runs in a central track. The ring is moved by a knob and is used to position the holes for the correct season.

        The solar declination scale is divided into 10-day intervals and marked by the initials of the months. The winter half of the year is on one side of the suspension ring; the summer half is on the other side. They are marked "W" and "S" respectively. The vernal equinox is set to March 10.

        There are two interior hour scales. Hour lines for the summer months are marked 4-12-8 and cross three vertical calendar lines. Hour lines for the winter months are marked 6-12-5, and also cross three vertical calendar lines.

        There are initials on the lines between the summer and winter dials: "S H W"

        Mathematical measurements show that the dial is made for the latitude of 52°.

        Signedinside ring: S H W
        Curatorial RemarksChristie's DC830/99 7175 engraved "SW" 7128 engraved"SHW"
        FunctionThe ring dial, or poke, finds the hour by means of the sun's altitude corrected for the seasonal declination.
        ProvenanceJoseph Drecker, Aachen, Germany, before 1928 (no. 195); Frederik Casparus Wieder, Noordwijk, The Netherlands, 1928; D. P. Wheatland, Topsfield, MA, 1959; gift to CHSI, ca. 1987.
        sleeve for vertical plate sundial and horary quadrant
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        Date: 1650-1675
        Object number: 7173a
        vertical disk sundial with nocturnal
        French
        Date: 17th Century
        Object number: 7318
        Gunter's quadrant with declinatory for 51°30'
        John Worgan
        Date: circa 1690
        Object number: 7483
        replica planispheric astrolabe by Bos 1597
        Johannes Bos
        Date: late 19th Century
        Object number: DW0595
        polyhedral sundial
        Italian
        Date: 1737
        Object number: 7279
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        Charles Bloud
        Date: circa 1665
        Object number: 7519
        de Rojas-type astrolabe
        Anthoine Mestrel
        Date: 1551
        Accessories: old velvet pouch
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        pillar sundial
        Turkish
        Date: 18th Century
        Object number: 7184
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        Roch Pacquellet
        Date: 1567
        Object number: 7377
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        French
        Date: second half of 16th century?
        Object number: DW0594
        bowl of Ahaz refracting, scaphe sundial
        Georg Hartman
        Date: 1548
        Object number: 7397
        miniature ivory diptych sundial
        French
        Date: mid 17th-late 17th Century
        Object number: 7496