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The Encyclopedia of Horology

Tool · German nocturnal and sundial

Nocturnal and Regiomontanus-type Sundial by Caspar Vopel

Partially verified

This gilt brass nocturnal and sundial, measuring 180 mm in length, was created by Caspar Vopel in Cologne in 1551. It functions as a multipurpose timekeeping and astronomical tool, featuring an elaborate nocturnal on one side and a Regiomontanus-type dial on the reverse. The nocturnal incorporates a calendar scale, zodiacal rings, and multiple indices, including a lunar volvelle with phase displays and life-cycle allegories. The sundial side features a latitude scale, shadow squares, and a meridian scale, all inscribed with Latin nomenclature. The instrument includes a handle engraved with a coat-of-arms and descriptive text. The source reports that certain components, specifically one top sight and the central alidade, are missing, and the thread for the dial arm is absent. The instrument is held in the collection of the British Museum.

The nocturnal side of the gilt brass instrument featuring the lunar volvelle and maker signature.
The nocturnal side of the gilt brass instrument featuring the lunar volvelle and maker signature. — © British Museum, London. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.mhs.ox.ac.uk
Category
Tool · German nocturnal and sundial
Maker / attribution
Caspar Vopel
Reference
Not recorded
Catalogue / lot identifier
MLA 1895, 3-19.1
Source-reported date
1551
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

Construction and Design

The instrument is composed of gilt brass and measures 180 mm in length. It serves a dual purpose, functioning as a nocturnal on one side and a Regiomontanus-type sundial on the other. The nocturnal side contains several concentric scales, including a calendar scale, zodiacal ring, and an index for solar and lunar time. The lunar index is pierced to represent moon phases and includes inscriptions correlating these phases to the life cycle.

The reverse face features an 'HORARIVM VNIVERSALE' for latitude calculation, utilizing shadow squares designated as 'VMBRA RECTA' and 'VMBRA VERSA'. The limb of the instrument is marked with astronomical and geometric quadrants. The handle is engraved with a coat-of-arms and Latin text detailing the nocturnal functions of the device.

Evidence for this section
  • “The instrument is a nocturnal on one side and a Regiomontanus dial on the other side.”
  • “The nocturnal has the handle at the 20th of August.”
  • “The handle is engraved with a coat-of-arms and with the inscription 'HOROMETRI DORSVM NOCTVRNAS HORAS CONIVNCT ? OPPOSITI ASPECTVS Q3 INDICAT'.”

Inscriptions and Markings

The instrument is extensively inscribed in Latin, denoting its function and astronomical utility. The nocturnal displays month names, zodiacal signs, and star symbols alongside planetary aspects such as 'OPPOSITVS', 'TRIGONVS', and 'TETRAGONVS'. The index plates are clearly labeled with 'INDEX SOLIS' and 'INDEX LVNAE'. The Big Bear constellation is marked with seven stars and labeled 'PLAVST VRSAE'.

The sundial side is inscribed with common hours and latitude scales ranging from 0 to 65. It bears the formal signature of the maker, Caspar Vopel, and identifies the place of manufacture as Cologne. The inscriptions on the handle emphasize the universality of the dial, noting its application for various regional latitudes.

Evidence for this section
  • “The names of the months are engraved in Latin on an inner circle and alternate with star symbols.”
  • “On the left hand side is also the signature 'CASPAR VOPELI<VS> FACIEBAT COLONIE AGRIPPI ANNO 1551'.”
  • “The back of the instrument has a Regiomontanus-type dial, inscribed 'HORARIVM VNIVERSALE'.”

Condition and Provenance

The British Museum acquired the instrument in 1895, where it is documented under registration number MLA 1895, 3-19.1. It is recorded in the 1981 catalog of European Scientific Instruments by F. A. B. Ward. The thread intended for the dial arm is also missing.

Comparisons are drawn to similar instruments, such as a nocturnal by the same maker formerly at auction and an example housed at the Museum of the History of Science in Oxford.

Evidence for this section
  • “The instrument was purchased in 1895 and is described in F. A. B. Ward, A Catalogue of European Scientific Instruments in the Department of Medieval and Later Antiquities of the British Museum (London, 1981), p. 57, no.151.”
  • “One of the sights at the top of the instrument is missing, as is probably a central alidade.”
  • “The thread for the dial arm is missing.”

Open research questions

  • What specific evidence links the missing thread and alidade to the original construction versus later loss?
  • Do the three star punches on the handle indicate a workshop mark or a functional alignment guide?

Source evidence

Recorded claims and source quotations for Nocturnal and Regiomontanus-type Sundial by Caspar Vopel
FieldSource-reported valueSource quotation
MakerCaspar Vopel“Signed by Caspar Vopel”
Date1551“Dated 1551”
Place of originCologne“Cologne”
MaterialGilt brass“Gilt brass”
Length180 mm“180 mm in length”
Inventory numberMLA 1895, 3-19.1“Registration no. MLA 1895, 3-19.1”
SignatureCASPAR VOPELI<VS> FACIEBAT COLONIE AGRIPPI ANNO 1551“CASPAR VOPELI<VS> FACIEBAT COLONIE AGRIPPI ANNO 1551”

Visible details

  • Includes a lunar volvelle with life phases inscribed as juvenile, virile, senile, and decrepit
  • Features a Regiomontanus-type dial with an 'HORARIVM VNIVERSALE' inscription
  • Contains shadow scales on the limb marked 'QVADRANS ASTRONOMICVS' and 'QVADRANS GAEOMETRICVS'
  • Engraved with a coat-of-arms on the handle

Research qualifications

  • The source notes the thread for the dial arm is missing
  • The source states that one sight and a central alidade are likely missing

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

Consulted source

Nocturnal And Sundial

Reviewed 2026-10-26 · Record d5d0f34def

Terms in this record

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

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