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The Encyclopedia of Horology

Tool · German astronomical compendium

Astronomical Compendium by Josua Habermel

Partially verified

This astronomical compendium, signed by Josua Habermel, dates to the late 16th century and is constructed from gilt and silvered brass, measuring 62 x 60 x 9 mm. The instrument consists of two hinged, approximately square leaves enclosing a central box. It incorporates an equinoctial sundial, a horizontal string gnomon sundial, and various volvelles. The outer face of the upper leaf features a compass rose and remains of a volvelle, while the inner face contains a lunar volvelle with foliage decoration. The central box houses a horizontal string gnomon dial and a compass with Latin markings and a classical head engraved on its underside. The lower cover displays tables of latitudes for several locations. The compendium is currently incomplete, missing rotating discs for the volvelles and the gnomon for the equinoctial dial.

The internal components of the astronomical compendium including the lunar volvelle, the equinoctial dial, and the central compass.
The internal components of the astronomical compendium including the lunar volvelle, the equinoctial dial, and the central compass. — Museum of the History of Science, Oxford. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.mhs.ox.ac.uk
Category
Tool · German astronomical compendium
Maker / attribution
Josua Habermel
Reference
Not recorded
Catalogue / lot identifier
41486
Source-reported date
Late 16th century
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

Structural Configuration

The compendium is configured as a box formed by two hinged square leaves. The structure incorporates an equinoctial dial, which is hinged between the upper cover and the central box. A folding arm on the surface below allows for the elevation of the equinoctial dial plate. The central box houses the horizontal dial and a magnetic compass.

The sides of the central box feature an incised rectangular decoration. Both leaves are secured by a hook clasp. The internal and external faces of the leaves are decorated with engraved foliage, particularly in the corners of the plates.

Evidence for this section
  • “The compendium has two approximately square hinged leaves enclosing a central box. Each leaf is fixed with a hook clasp.”
  • “The only decoration on the sides of the central box is an incised rectangle.”

Dials and Volvelles

The outer face of the upper leaf holds a circular compass rose and the remnants of a volvelle, which is missing its rotating disc. The fixed scales provide hours from 1 to 24 and 8 to 16. The inner face features a lunar volvelle, also incomplete, designed to track the moon's age through a series of fixed scales and a missing rotating disc.

The equinoctial dial plate, located between the box and the cover, features an hour scale running from 3 to 12 to 9. The underside of this plate includes a scale for latitude marked 'Eleuatio Poli'. The central box contains a horizontal string gnomon dial, with the gnomon anchored by the equinoctial dial plate.

Evidence for this section
  • “compendium is of a standard pattern, and includes an equinoctial sundial , a horizontal string gnomon sundial , volvelles and latitude tables.”
  • “The volvelle would have been used to convert between equal and Italian or Babylonian hours, and to give the lengths of night or day respectively.”

Signature and Documentation

The instrument is signed by Josua Habermel on the outer face of the lower cover leaf. The lower cover also carries a table of latitudes for eighteen locations, titled 'Eleuatio Poli'. The provenance is identified as the Lewis Evans Collection, specifically item G. 410.

and includes an indication of magnetic variation. The underside of the compass bowl is engraved with a classical head, adding to the decorative elements of the interior, alongside the foliage engraving found on the dial plates.

Evidence for this section
  • “It is titled 'Eleuatio Poli' and carries the signature 'Ios?a Habermel'.”
  • “Provenance: Lewis Evans Collection G. 410.”

Open research questions

  • What is the specific nature of the compass variation indication found on the compass base?
  • Can the missing volvelle rotating discs be reconstructed based on similar surviving Habermel instruments?

Source evidence

Recorded claims and source quotations for Astronomical Compendium by Josua Habermel
FieldSource-reported valueSource quotation
MakerJosua Habermel“Signed by Josua Habermel”
DateLate 16th century“Late 16th century”
MaterialsGilt and silvered brass“Gilt and silvered brass”
Dimensions62 x 60 x 9 mm“62 x 60 x 9 mm”
Inventory number41486“Inventory number 41486”
Compass markingsLatin“marked in Latin with the four cardinal directions”

Visible details

  • Hinged leaves with hook clasps
  • Engraved foliage in corners of dial plates
  • Compass bowl with Latin markings for cardinal directions
  • Folding arm for elevating the equinoctial dial plate

Research qualifications

  • The rotating discs of the volvelles are missing
  • The gnomon for the equinoctial dial is missing

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

Consulted source

Astronomical Compendium

Reviewed 2026-10-26 · Record 905ff1b6c5

Terms in this record

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

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