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The Encyclopedia of Horology

Tool · German gunner's compendium

Gunner's Compendium

Partially verified

This later 16th-century German gunner's compendium is constructed of gilt brass and measures 143 x 143 mm. Designed as a multifunction instrument for artillery use, it includes a gunner's sight, plummet, quadrant, shadow square, horizontal sundial, and a hemispherical compass. The square plate features extensive engraving of scrollwork, leaves, and fruit, alongside a small vignette of a gunner with a cannon. The instrument contains numerical tables for converting units of length, such as feet and paces, as well as multiple scales and rules, including an ungraduated 208 mm rule with a sight. Although intended to stand vertically, the original support is absent, and the instrument currently exhibits several losses, including the folding gnomon, the compass needle, the plumb-bob, and the sliding sight piece.

Gunner's compendium, unsigned, German, later 16th century, held by the Museum of the History of Science, Oxford.
Gunner's compendium, unsigned, German, later 16th century, held by the Museum of the History of Science, Oxford. — Museum of the History of Science, Oxford. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.mhs.ox.ac.uk
Category
Tool · German gunner's compendium
Maker / attribution
Not established
Reference
Not recorded
Catalogue / lot identifier
46878
Source-reported date
Later 16th century
Source-reported place
Germany

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

Instrument Configuration

The compendium is a square gilt brass plate, designed with a perforated central slit for a sliding sight, which is now missing. The instrument is intended to stand vertically, although the necessary stand is lost. It integrates several functional components, including a shadow square and a quadrant, both of which pivot around a central point, and a hemispherical compass suspended from two pivot points.

The instrument's surface is heavily decorated with engraved scrollwork and foliage. A specific vignette depicting a gunner operating a cannon signals the intended artillery context. Various scales are engraved along the edges and within the slots, featuring division to twelfth-inch increments, though their precise geometrical function remains a subject of ongoing investigation due to non-standard alignments and unresolved mechanical configurations.

Evidence for this section
  • “The square format of this instrument is unusual and includes several different components”
  • “All otherwise free space on its two faces are occupied by scrollwork and leaf and fruit engraved decoration”
  • “The sliding sight is now lost but would have been placed in the instrument's central slit”

Mathematical and Astronomical Features

The instrument includes complex tables for converting feet (Schuh) to paces (Schritt). These tables demonstrate historical relationships to artillery range tables, such as those found in Leonhard Zubler’s work. The numerical data provided on the plate contain several inaccuracies in the calculations, suggesting either errors in the original execution or a rationale that remains obscure.

Additionally, the reverse side features a horizontal sundial identified with the mark 'BOIS 48 GRA'. While the sundial is present, its folding gnomon is lost. The instrument's construction includes a shadow square and quadrant, though the current arrangement prevents them from functioning as expected, as the rule edges do not pass through the centre in the instrument's present state.

Evidence for this section
  • “There is also a shadow square whose sides run 0 to 12”
  • “Two of these scales could also be used with the ungraduated rule if it was fixed in the corner of the instrument.”
  • “Also on the reverse of the instrument is a horizontal sundial marked 'BOIS 48 GRA'”

Condition and Losses

The compendium has sustained significant losses since its production. Essential operational components such as the folding gnomon for the sundial, the compass needle, the plumb-bob, and the sliding sight piece are missing. The original stand required for the instrument to function in its intended vertical orientation is also absent.

These losses, combined with the presence of ungraduated scales and rules that do not align with the geometrical centres of the shadow square or quadrant, complicate the functional analysis of the device. Consequently, several features, including the 'SHVC' table on the reverse, have not been adequately explained in the context of the instrument's primary utility.

Evidence for this section
  • “the necessary support is now missing, as are various other elements such as the sliding piece for the sight , the plumb-bob for the plummet , the folding gnomon of the sundial and the compass needle.”
  • “This table has not been adequately explained.”

Open research questions

  • What is the definitive mechanical relationship between the rules and the quadrant/shadow square?
  • What is the specific intended meaning and derivation of the 'SHVC' table on the reverse?

Source evidence

Recorded claims and source quotations for Gunner's Compendium
FieldSource-reported valueSource quotation
MaterialGilt brass“Gilt brass”
Dimensions143 x 143 mm“143 x 143 mm”
OriginGerman“German”
DateLater 16th century“Later 16th century”
Inventory number46878“Inventory number: 46878”
Sundial inscriptionBOIS 48 GRA“horizontal sundial marked 'BOIS 48 GRA'”
ProvenanceLewis Evans Collection G. 582“Provenance: Lewis Evans Collection G. 582.”

Visible details

  • Small engraved vignette of a gunner with a cannon
  • Hemispherical compass bowl approximately 18 mm in diameter
  • Multiple numerical tables engraved directly onto the plate surface
  • Two-faced design with perforated central slit

Research qualifications

  • The exact use and construction of the numerical tables and ungraduated scales remain uncertain.
  • The original orientation and configuration of the rules and scales are subject to unresolved mechanical questions.

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

Consulted source

Gunner's Compendium

Reviewed 2026-10-26 · Record 7bb430f636

Terms in this record

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