Italian Astrological Instrument

Technical characteristics

Date

circa 1500

Type

Italian astrolabe

Origin

Italian

Diameter

95 mm

Signature

Unsigned

Place recorded

Italy

Design

Visible features

• The rete is centered around an eight-leaf flower motif. • The limb is graduated into four 90-degree quadrants. • The reverse features a complex system of eight stacked brass volvelles.

The Volvelle System

The reverse of the instrument features an elaborate assembly of eight concentric, rotating brass volvelles. The limb is engraved with the twelve astrological houses, each identified by name and number. The first volvelle includes a 365-day calendar scale with month names, and a zodiac scale with the first point of Aries corresponding to March 16th. Inner circles indicate ruling planets, three for every sign, along with associations for water, earth, fire, or wind. Subsequent volvelles are engraved with names of planets, including 'IVPITER', 'MARSE', 'VENVS', 'MERQRIO', and 'SOL'. The final volvelle consists of a double arm depicting the head and tail of the Dragon, labeled 'CAPVT' and 'CAVDA', used to track lunar phases and astrological positions.

Construction and Design

The instrument is constructed from thin brass plates. On the obverse, a rete and a single-arm rule are riveted to the main plate. The plate displays tropics, equator lines, almucantars, azimuth lines, and unequal hour lines. The space between the horizon and the first and last hour lines is shaded. A faint inscription, possibly representing latitude, is visible at the center of the plate. The rete pattern includes 28 star pointers shaped as round-ended lobes with small stars, supplemented by 13 additional stars etched into the rete design. The rule contains an unequal scale marked only with 'SE' and 'ME'. The suspension system for the instrument is currently missing.

Provenance and Documentation

This object is held by the Museum of the History of Science in Oxford under the inventory number 45127. It is catalogued as an astrological instrument rather than an observational one. The description provided by Ilaria Meliconi emphasizes that the instrument deviates from standard astrolabe usage due to its focus on planetary positions in relation to traditional astrological houses. Research documentation includes a reference to R. T. Gunther's 'The Astrolabes of the World' (1932). The instrument remains unsigned, and its precise origin is attributed generally to Italian workshops of the period.

Identification

Inventory number

45127

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.