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The Encyclopedia of Horology

Tool · Portable equatorial sundial

Portable equatorial sundial by Lorenz Gräsl

Partially verified

This portable equatorial sundial is attributed to the German maker Lorenz Gräsl (ca. 1740–1805) and is dated circa 1772–90. The object originates from the Augsburg region and is currently held in the collection of The Metropolitan Museum of Art under the accession number 03.21.19. Constructed entirely of brass, the instrument measures 3 1/2 by 3 1/4 by 3 1/8 inches (8.9 by 8.3 by 7.9 cm).

Portable equatorial sundial constructed of brass, featuring an equatorial ring and plumb bob mechanism.
Portable equatorial sundial constructed of brass, featuring an equatorial ring and plumb bob mechanism. — The Metropolitan Museum of Art, New York. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
orbiscollectibles.com
Category
Tool · Portable equatorial sundial
Maker / attribution
Lorenz Gräsl
Reference
Not recorded
Catalogue / lot identifier
03.21.19
Source-reported date
ca. 1772–90
Source-reported place
Germany

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Design and Construction

The sundial is an equatorial type, engineered for portability and precise alignment. The instrument is constructed from brass, featuring a square base that acts as the foundation for the various articulated components. The layout includes a central dial plate and a vertical assembly supporting the equatorial ring, which is calibrated to display time through a series of etched Roman numerals.

To ensure accuracy, the instrument includes a plumb bob suspended from a decorative support structure. This mechanism allowed the user to level the base, which is supported by small, distinct feet, ensuring that the ring remained properly aligned relative to the Earth's axis. The design incorporates folding elements that allow the device to be packed compactly for travel.

Evidence for this section
  • “Portable equatorial sundial”
  • “Overall: 3 1/2 × 3 1/4 × 3 1/8 in. (8.9 × 8.3 × 7.9 cm)”

Origin and Attribution

The object is attributed to the maker Lorenz Gräsl, who was active between approximately 1740 and 1805.

The Metropolitan Museum of Art documents this item as part of their European Sculpture and Decorative Arts collection. The dating is established as circa 1772–90, placing the object within the later portion of Gräsl's documented active career.

Evidence for this section
  • “Lorenz Gräsl (German, ca. 1740–1805)”
  • “German, Augsburg”
  • “ca. 1772–90”

Documentation and Repository

The sundial is held by The Metropolitan Museum of Art under the identification number 03.21.19. The museum's records identify the materials and dimensions of the piece, confirming its status as a documented institutional artifact.

While the record provided by Orbis Collectibles summarizes the museum's data, it notes that the attribution and specifications should be cross-referenced with independent horological literature to confirm the object's place within the wider typology of equatorial sundials produced by Gräsl or his contemporaries in Augsburg.

Evidence for this section
  • “The Metropolitan Museum of Art holds this object as 03.21.19”
  • “03.21.19”
  • “confirm the wider type, maker attribution and specifications against horological references”

Open research questions

  • How does this specific specimen compare to other known equatorial sundials signed by Lorenz Gräsl?
  • What specific latitude adjustments were intended for the primary market of this instrument?

Source evidence

Recorded claims and source quotations for Portable equatorial sundial by Lorenz Gräsl
FieldSource-reported valueSource quotation
MakerLorenz Gräsl“Lorenz Gräsl (German, ca. 1740–1805)”
Dateca. 1772–90“ca. 1772–90”
Dimensions3 1/2 × 3 1/4 × 3 1/8 in. (8.9 × 8.3 × 7.9 cm)“Overall: 3 1/2 × 3 1/4 × 3 1/8 in. (8.9 × 8.3 × 7.9 cm)”
OriginAugsburg, Germany“German, Augsburg”
Holding InstitutionThe Metropolitan Museum of Art“The Metropolitan Museum of Art”
Accession Number03.21.19“03.21.19”

Visible details

  • Articulated equatorial ring with roman numeral markings
  • Integrated leveling device including a plumb bob
  • Brass base with small turned feet for stability

Research qualifications

  • The maker attribution to Lorenz Gräsl requires further verification against broader horological literature
  • The specific date range is attributed and may be subject to future scholarly revision

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Portable equatorial sundial

Reviewed 2026-11-02 · Record c7fd50273e

Terms in this record

Glossary explanations for terms named in this object’s record.

Other portable equatorial sundial records