Humfrey Cole Nocturnal

Technical characteristics

Date

circa 1575

Type

English nocturnal

Maker

Humfrey Cole

Handle

Pierced fleur-de-lis with 'W F'

Diameter

95 mm

Material

Gilt brass

Signature

H Cole

Place recorded

London

Maker / attribution

Humfrey Cole

Design

Visible features

• Pierced fleur-de-lis handle with initials 'W F' • Sun effigy at 12 o'clock on the front volvelle • Scrollwork engraving on the front disc center • Inscribed 'STELLA POLARIS' and 'INDEX HORA NOCTIS' on the index arm

Construction and Design

The nocturnal is constructed of gilt brass and measures 95 mm in diameter. It is distinguished by a central disc with volvelles and indices on both the front and the reverse. A small handle, shaped as a pierced fleur-de-lis and marked with the initials 'W F', is attached to the edge of the disc. The front features a circular calendrical scale showing Latin month names and their respective day counts, with December notably featuring 31 1/4 days to account for the leap year. A volvelle situated in the center of the front scale provides an hour scale, numbered 1 to 12 twice in an anticlockwise direction. Alternating teeth on the volvelle denote full and half-hour increments. A sun effigy at the 12 o'clock position serves as an index to set the date. The central area of this side is decorated with engraved scrollwork, and an index arm, inscribed 'STELLA POLARIS' and 'INDEX HORA NOCTIS', rotates over the volvelle.

Provenance and Documentation

The nocturnal was acquired by the British Museum in 1857 and is catalogued under the inventory number MLA 1857,11-16.2. The instrument has been the subject of several scholarly records, including an entry in R. T. Gunther’s 'The Great Astrolabe and other Scientific Instruments of Humphrey Cole', published in Archaeologia in 1927. Additional documentation is provided by F. A. B. Ward in 'A Catalogue of European Scientific Instruments in the Department of Medieval and Later Antiquities of the British Museum', published in 1981. These texts confirm the attribution to Humfrey Cole and detail the instrument's design features as they appear in the collection.

Functional Scales and Tidal Prediction

The reverse of the instrument provides secondary functionality for celestial and tidal calculation. It includes three distinct circular scales: an outermost degree scale marked from 0 to 360 degrees, a 24-hour scale, and a 32-point compass rose featuring a fleur-de-lis for North. The central component on this side is a fixed disc indicating the lunar age from 1 to 30, coupled with a rotating volvelle and an aperture displaying the phases of the moon. The integration of these scales enables the prediction of high tide at a specific port, provided the port's direction is known. This function aligns with methods documented in Digges' 'Prognostication', which was printed in 1555 by Thomas Gemini. The plate on the reverse also includes markings for planetary aspects, although this feature is noted as being incomplete.

Identification

Inventory Number

MLA 1857,11-16.2

Source note

Facts transcribed from the linked source listing or collection record. Attribution and specifications are source-reported and have not been independently authenticated.

Catalogue references

No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.