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The Encyclopedia of Horology

Tool · French nocturnal

Nocturnal with sun and moon dial

Partially verified

This gilt brass nocturnal, measuring 59 mm in diameter, is an unsigned and undated instrument held by the British Museum. It is attributed to France and potentially the late 16th century based on stylistic and linguistic comparisons. The instrument serves multiple functions, incorporating a nocturnal, a horizontal sun and moon dial on its front face, and a vertical pin gnomon dial on the reverse. Its complex design features a circular disc with various volvelles, zodiacal and calendrical scales, and an attached compass with a swivelling lid. The reverse side includes unique astrological tables for tracking lucky and unlucky days, though some of the symbolic designations remain not fully understood. The instrument is accompanied by a tooled red leather case featuring a green velvet lining.

A gilt brass nocturnal and its tooled red leather storage case.
A gilt brass nocturnal and its tooled red leather storage case. — © British Museum, London. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.mhs.ox.ac.uk
Category
Tool · French nocturnal
Maker / attribution
Not established
Reference
Not recorded
Catalogue / lot identifier
MLA 1867,3-10.1
Source-reported date
Late 16th century ?
Source-reported place
France

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 Primary Functions

The nocturnal consists of a circular gilt brass disc, 59 mm in diameter, equipped with a handle and a series of rotating volvelles. The front face functions as both a nocturnal and a horizontal sun and moon dial, utilizing a zodiacal scale and a calendrical scale marked by month initials. A revolving ring, connected by four radial arms, displays the moon's age, while an index arm marked 'LIGNE DE FOY' facilitates readings across an hour scale.

The front further includes a folding gnomon and a circular aperture for viewing moon phases. A compass with an engraved, swivelling lid is also fixed to the disc. The instrument was designed for use at a latitude of approximately 40 degrees, and its central suspension apparatus is calibrated to the date of May 20.

Evidence for this section
  • “The instrument consists of a circular disc with a handle and several volvelles.”
  • “The front is laid out as a nocturnal and a horizontal sun and moondial.”
  • “Attached to this disc is a compass marked with the cardinal points and with a swivelling engraved lid.”

Astrological and Reverse Features

The reverse of the disc serves as a vertical pin gnomon dial, although the gnomon is currently broken. Surrounding this area is an hour scale divided into quarters and halves. Central to the reverse are two volvelles providing astrological information. These tables list days of the month categorized as lucky or unlucky, indicated by specific letters ('L', 'P', 'LP') and accompanied by an index arm.

These tables are organized by zodiacal signs and month initials, yet the specific definitions of these abbreviations are not presently resolved. The inclusion of these astrological tables distinguishes the instrument from more conventional nocturnals.

Evidence for this section
  • “The reverse is laid out for a vertical pin gnomon dial with the folding gnomon now broken off.”
  • “The larger one, to which the folding pin gnomon was once attached, has scales indicating the lucky and unlucky days in a month”
  • “The meaning of 'L' , 'P' and 'LP' and the strange sequence for the unlucky days in January are not fully understood yet.”

Provenance and Presentation

The instrument is housed in a tooled red leather case with a green velvet interior, which protects the gilt brass surfaces. It was acquired by the British Museum in 1867 and holds the registration number MLA 1867,3-10.1.

Documentation regarding the object is found in F. A. B. Ward's 1981 publication, 'A Catalogue of European Scientific Instruments in the Department of Medieval and Later Antiquities of the British Museum'. The lack of signature or date requires reliance on comparison with similar documented pieces for historical context.

Evidence for this section
  • “The instrument has a tooled red leather case with a green velvet lining.”
  • “The instrument was purchased in 1867 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. 27.”
  • “This instrument is neither signed nor dated, but comparison with similar instruments and the language used make it likely that it was made in the late 16th century in France.”

Open research questions

  • What specific astrological definitions correspond to the 'L', 'P', and 'LP' notations?
  • Does the broken pin gnomon on the reverse indicate a specific period of structural modification or damage?

Source evidence

Recorded claims and source quotations for Nocturnal with sun and moon dial
FieldSource-reported valueSource quotation
MaterialGilt brass“Gilt brass”
Dimensions59 mm in diameter“59 mm in diameter”
OriginFrench“French”
Inventory numberMLA 1867,3-10.1“MLA 1867,3-10.1”
DateLate 16th century“Late 16th century ?”
Astrological functionIncludes tables of lucky and unlucky days“highly unusual tables of lucky and unlucky days on the reverse which serve astrological purposes”

Visible details

  • Includes an integrated compass with swivelling lid
  • Features a folding gnomon on the front disc
  • Constructed of gilt brass with multiple revolving volvelles
  • Accompanied by a tooled red leather case with green velvet lining

Research qualifications

  • The exact date remains uncertain ('Late 16th century ?')
  • The meaning of 'L', 'P' and 'LP' symbols on the astrological tables is not fully understood

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

Consulted source

Nocturnal

Reviewed 2026-10-26 · Record 0ebd166609

Terms in this record

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

Other french nocturnal records