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The Encyclopedia of Horology

Tool · Italian nocturnal and sundial

Nocturnal and sundial by Girolamo della Volpaia

Partially verified

This brass nocturnal and sundial, measuring 97 mm in diameter, is signed by Girolamo della Volpaia and dated 1567. The instrument is constructed from three superimposed circular disks, with a central sighting hole and a rotating pointer. The nocturnal side features a zodiacal calendar scale and a volvelle consisting of two discs, the upper featuring 24 teeth and various scales, including a month scale and an inscription reading 'MEDIA NOX PER TOTVM ANNVM'. The second face functions as a sundial and quadrant, displaying an hour diagram for Italian hours, a 90-degree scale, and latitude information. The instrument includes a suspension mount resembling an astrolabe throne. It is calibrated for a latitude of 43° 44', corresponding to Florence, and incorporates multiple inscriptions, including the signature in a scroll on the second face.

The nocturnal side of the instrument showing the zodiacal calendar, central volvelle, and the rotating pointer marked 'HOROLOGIVM NOCTVRNVM'.
The nocturnal side of the instrument showing the zodiacal calendar, central volvelle, and the rotating pointer marked 'HOROLOGIVM NOCTVRNVM'. — Istituto e Museo di Storia della Scienza, Firenze. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.mhs.ox.ac.uk
Category
Tool · Italian nocturnal and sundial
Maker / attribution
Girolamo della Volpaia
Reference
Not recorded
Catalogue / lot identifier
3811
Source-reported date
1567
Source-reported place
Italy

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

Nocturnal Construction

The nocturnal side of the instrument consists of three superimposed brass disks of varying diameters. The central disk is marked with a zodiacal calendar scale, while the inner volvelle features two components: a lower disk with a 24-hour scale and an upper disk featuring 24 edge teeth. A pivoting long pointer marked 'HOROLOGIVM NOCTVRNVM' rotates around the central sighting hole.

Various concentric scales are engraved on the upper disk, including a month scale and numeric sequences. An inscription, 'MEDIA NOX PER TOTVM ANNVM', is found in the fourth ring, with a matching 'MEDIA NOX' marker on the first disk to facilitate time calculation using the polar star.

Evidence for this section
  • “The nocturnal is composed of a central circular disc divided with a zodiacal calendar scale”
  • “the upper with its edge notched with 24 teeth.”
  • “a large rule is mounted so as to rotate round the central sighting hole marked 'HOROLOGIVM NOCTVRNVM'.”

Sundial Face and Quadrant

The reverse side of the instrument serves as a sundial and quadrant, designed for latitudes 43° and 44°. It features a diagram for Italian hours, marked 9 to 24, and includes a 90-degree quadrant scale divided into single-degree increments.

Surrounding the main diagram are calendar scales and a solar motion table labeled 'SOL IN SIGNO'. The signature of Girolamo della Volpaia is present in a scroll, alongside an inscription indicating the latitude and specific line markings for post-meridiem time.

Evidence for this section
  • “The second face of the instrument carries at the centre the hour diagram for an Italian hours dial (9 to 24)”
  • “Beneath the diagram is a scale of 90? reading to one degree”
  • “To the left of the diagram is the signature written in a scroll”

Mounting and Provenance

The instrument includes a decorative suspension mount, or throne, integrated into the central plate, mirroring the style of an astrolabe. This component allows for the tool to be held or suspended during use.

Records indicate the provenance of the instrument traces back to Dott. Filiberto Catinari of Fermo, acquired in 1992. The object is currently held in the collection of the Istituto e Museo di Storia della Scienza in Florence.

Evidence for this section
  • “Two scrolled pinhole sights are set on the top line of the instrument and above them is a suspension mount/handle similar in form to the 'throne' of an astrolabe”
  • “Provenance: Dott. Filiberto Catinari, Fermo. 4/3/92.”

Open research questions

  • What specific historical significance does the numeric sequence on the nocturnal disk hold?
  • Are there variations in the accuracy of the Italian hour dial across the range of latitudes supported?

Source evidence

Recorded claims and source quotations for Nocturnal and sundial by Girolamo della Volpaia
FieldSource-reported valueSource quotation
MakerGirolamo della Volpaia“Signed by Girolamo della Volpaia”
Date1567“Dated 1567”
PlaceFlorence“Florence”
Diameter97 mm“97 mm in diameter”
Inventory Number3811“Inventory number: 3811”
Latitude Calibration43° 44'“calibrated for a latitude of 43? 44', corresponding to Florence”
ProvenanceDott. Filiberto Catinari, Fermo“Provenance: Dott. Filiberto Catinari, Fermo. 4/3/92.”

Visible details

  • Central circular disc features a zodiacal calendar scale with 0° Aries at March 10
  • Upper disk of the nocturnal is notched with 24 protruding teeth
  • Second face includes a quadrant scale of 90 degrees
  • Suspension mount designed as an astrolabe-style throne

Research qualifications

  • The exact origin of the instrument beyond the attribution to Florence remains subject to historical research
  • The precise function of the complex numeric inner scales on the nocturnal face is not fully detailed in the source

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

Consulted source

Nocturnal And Sundial

Reviewed 2026-10-26 · Record 8198a149e3

Terms in this record

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

Other italian nocturnal and sundial records