ring sundial
Datedate 1693
Inventory Number7466
ClassificationSundial
Subject
Maker
I.A.M.
Place of Origin
Dimensions6.2 × 5.6 × 1.7 cm (2 7/16 × 2 3/16 × 11/16 in.)
Material
AccessoriesNone
Description2" diameter brass Ring Dial. A declination scale is divided into four divisions per month on the exterior surface and a time scale in Arabic numerals subdivided into 1/2 hour increments is on the interior surface of the ring. The hour lines are slopping with seven circumferential lines indexed by months of the year. The dial is designed for a latitude of approximately 46°. There is a suspension loop that is not continuous. The vernal equinox (6AM at 0° elevation) is set for approximately March 14.,circular
2" Diameter Brass Ring Dial (Poke) with sliding band having one aperture by I.A.
2" Diameter Brass Ring Dial (Poke) with sliding band having one aperture by I.A.
SignedSigned "I.A.M." / "1693" on the interior ring surface on opposite sides of the slit
InscribedThe latitudes of 10 cities are punched into the external surface of the ring.
Curatorial RemarksAppraised by Brieux, 9/24/84: $1000
FunctionTime-finding by measurement of the sun's altitude, corrected for declination.
ProvenanceHarrold E. Gillingham, Philadelphia, Pennsylvania, purchased from Gertrude Hamilton (Mercator), Paris, 1929. David P. Wheatland purchased from Gillingham, 1949. Donated to CHSI 1985.
Historical AttributesZinner, p. 433, lists a ring dial by IAM dated 1693 associated with Mercator (other ring dials by IAM are dated 1695, 1696, 1699 and 1704). A similar dial dated 1688 is listed in Ward, p 62.
