ring sundial
Date1700
Inventory Number7908
ClassificationSundial
Subject
Maker
I Z
Collector
Harold C. Ernst
1856 - 1922
Collector
Ernst Collection of Sundials
founded circa 1900
Place of Origin
Dimensions1 × 5.8 × 4 cm (3/8 × 2 5/16 × 1 9/16 in.)
Material
AccessoriesNone
Description1 1/2" Diameter Brass Ring Dial (Poke) with non-circular time scale by IZ
1 1/2" diameter brass Ring Dial with an additional curved section fastened inside and forming a portion of the time scale. A declination scale is divided into four divisions per months on the exterior surface and a time scale in Arabic numerals subdivided into 1/2 hour increments on the interior surface of the ring. The ring is made from a ring of brass with a second strip of brass rivited interior to the ring to compensate for higher sun elevations. The dial is designed for a latitude of approximately 48.4° (Augsburg?). The vernal equinox is set for approximately March 21.,circular
1 1/2" diameter brass Ring Dial with an additional curved section fastened inside and forming a portion of the time scale. A declination scale is divided into four divisions per months on the exterior surface and a time scale in Arabic numerals subdivided into 1/2 hour increments on the interior surface of the ring. The ring is made from a ring of brass with a second strip of brass rivited interior to the ring to compensate for higher sun elevations. The dial is designed for a latitude of approximately 48.4° (Augsburg?). The vernal equinox is set for approximately March 21.,circular
SignedSigned with mark of a cross and "IZ" on end of interior bracket
Curatorial RemarksATAN(18.7/16.6)=48.4° latitude
FunctionTime-finding by measurement of the sun's altitude, corrected for declination.
ProvenanceHarold Clarence Ernst, MD, Boston, c. 1900-1922 (no. 70); Mrs. Ellen L. Ernst (his widow), Jamaica Plain, MA, 1922; on loan to the Museum of Fine Arts, Boston, 1923-1938; gift to Harvard College Observatory, 1938; transfer to CHSI, 1964.
Johann Nepomuk Schrettegger
Date: circa 1800
Accessories: case
Object number: 7090
