floating sundial
Datecirca 1823
Inventory Number7233
ClassificationSundial
Subject
Maker
Samuel Porter
Place of Origin
Dimensions3.4 × 6.3 × 6.3 cm (1 5/16 × 2 1/2 × 2 1/2 in.)
Material
AccessoriesNone.
DescriptionFloating Magnetic Dial in dark wooden case with cover. Floating magnetic compass card with gnomon at an angle of approximately 52°. The chapter ring is printed on the floating compass card with hours marked from IIII to XII to VIII with 15 minute subdivisions. The compass magnet is offset from North by approximately 25° W to compensate for magnetic deviation. The compass rose is divided into 16 points.,circular
SignedSigned "S. Porter, Fecit." printed on dial face.
InscribedA paper label glued to the inside of the cover reads: "Floating on an Agate Cap" / "Patronized by the" / "KING" / "PORTER'S MAGNETIC" / "SUN DIAL"
Curatorial RemarksChristie's DC830/230. ATAN(12/9.2) =52.5° gnomon elevation
FunctionThe local time is indicated by the shadow of a self-orienting gnomon mounted on a magnetic compass card. This design is intended to be used at one specific latitude and magnetic deviation.
ProvenanceHarrold E. Gillingham, Philadelphia, Pennsylvania, purchased in London, 1923. David P. Wheatland purchased from Gillingham, 1949. Donated to CHSI, c. 1985.
