Astrolabe by Johann Anton Linden

Technical characteristics

Date

ca. 1590

Type

Latin-inscribed astrolabe

Maker

Johann Anton Linden (?)

Place

Heilbronn (?)

Material

Gilt brass

Latitudes

46°0' to 55°0'

Provenance

Presented by Lewis Evans in 1924

Rete Stars

34

Place recorded

Heilbronn (?)

Maker / attribution

Johann Anton Linden

Design

Visible features

• Rete marked with 34 star locations using flamant pointers. • Six scales on the back include altitude and shadow squares. • Alidade tips feature ornate carved decoration. • Rule is single-ended and counter-changed with decorative engraving.

Construction and Design

The astrolabe is composed of gilt brass, featuring a simple throne type attached to an integrated base. The suspension assembly consists of a round cross-section ring and a rotating pin-type shackle joined via a U-shaped bracket. The mater and limb are fabricated as a single-piece construction. The limb itself contains two primary circular, concentric scales: an equal hours scale numbered 1 to 12 at one-hour intervals, and a degree scale ranging from 0 to 90 degrees at 10-degree increments. The instrument includes an ornate rete that displays 34 stars, identified by flamant pointers. The zodiacal signs are engraved along the ecliptic band. The rete is secured by a pin and wedge assembly, both of which feature decorated heads. Two plates are included, offering latitude settings between 46°0' and 55°0'. The internal notch for fixing the tympan position is situated at the throne.

Provenance and Documentation

The history of the instrument is documented through its inclusion in the History of Science Museum, University of Oxford, under inventory number 48380. The object was formally acquired by the museum in 1924 through a presentation by Lewis Evans. Further records indicate that Evans had previously purchased the astrolabe from a dealer named Gerard, operating out of Monte Carlo, in 1901. This provenance data provides a limited history of the object prior to its institutional integration. The catalogue maintains the attribution to Johann Anton Linden and the suggested manufacture location of Heilbronn, though both descriptors are qualified with uncertainty in the official report.

Functional Scales and Components

The back of the astrolabe is equipped with six functional scales designed for astronomical and mathematical calculations. These include an altitude scale, zodiacal sign divisions, a calendar scale, and a shadow square. The altitude scale is positioned as the outermost ring, while the zodiacal and calendar scales occupy the circular bands immediately within. The shadow square, which is divided into 12 fingers with intervals of 3, is located in the lower portion of the back. Additionally, the upper quadrants contain scales for unequal hours. The instrument utilizes a single-ended, counter-changed rule and a double-ended, counter-changed alidade. The alidade is noted for its rigid construction with a single sight and ornately carved tips, while the rule features minor decorative engraving without additional sighting components.

Identification

Inventory Number

48380

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.