Horizontal Dial, 1585

Technical characteristics

Date

1585

Type

Italian horizontal dial

Maker

Carlo Plato

Material

Gilt brass

Provenance

Octavius Morgan

Inscription

Romae anno d ni 1585

Design feature

Pivoted compass

Place recorded

Rome

Maker / attribution

Carlo Plato

Design

Visible features

• The dial is made of gilt brass with a diameter of 90 mm. • A centrally located pin gnomon is visibly bent. • The compass is mounted within a pivoting frame for bidirectional use. • Engravings include Latin and Italian wind names on opposite sides of the disc.

The Pivoted Compass

A key component of this instrument is the revolving compass designed to function when the dial is flipped. This compass is inscribed with the initials of wind names in Italian: 'P' for Ponente, 'M' for Maestro, 'T' for Tramontana, 'G' for Greco, 'S' for Scirocco, 'O' for Ostro, and 'Ga' for Garbino. To ensure it remains horizontal regardless of the dial's orientation, a weight is incorporated into the bottom of the compass housing. The compass currently exhibits a configuration error where it is rotated by 90 degrees from its intended position. The bottom of the compass casing carries the inscription 'Romae anno d ni 1585', documenting the place and year of production in Rome.

Construction and Dial Layout

The instrument comprises a 90 mm diameter gilt brass disc engraved on both sides to serve as a horizontal sundial. The dial employs a pin gnomon to indicate various timekeeping systems. On the Latin-inscribed side, it tracks Babylonian hours via continuous lines and planetary hours using punctuated lines. The disc is engraved with cardinal points and wind names in Latin around the limb, specifically 'SEPTE TRIO', 'Boreas', 'SOLANVS', 'Eurus', 'MERIDIES', 'Aphricus', 'FAVONIVS', and 'Circius'. The reverse side utilizes Italian terminology for wind names, listing 'TRAMO TANA', 'Greco', 'LEVA TE', 'Scirocco', 'OSTRO', 'Garbino', 'PONE TE', and 'Maestro'. This side features a pin gnomon dial for Italian hours from 9 to 23 and common hours from 4 to 12 a.m. and 1 to 8 p.m. The gnomon on this side is observed to be bent, impacting its current state. The dial is also inscribed with the latitude information 'Polus 42 Graduu' on both faces.

Provenance and Documentation

The object is held in the collection of the British Museum under the registration number MLA 1888, 12-1.292. The dial entered the museum's holdings through the bequest of Octavius Morgan. It is catalogued in the specialized study by F. A. B. Ward, titled 'A Catalogue of European Scientific Instruments in the Department of Medieval and Later Antiquities of the British Museum', published in 1981. The entry in the catalogue serves as the primary reference for the object's history and identification within the British Museum. The instrument is attributed to Carlo Plato based on the construction of the dial and the specific arrangement of the winds and cardinal points, which aligns with his recorded output of scientific instruments in 16th-century Rome.

Identification

Reference

MLA 1888, 12-1.292

Inventory Number

MLA 1888, 12-1.292

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.