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The Encyclopedia of Horology

Nuremberg, Not recorded · fl. 1550–1597

Grüber, Hans

Partially verified

Maker of clocks, watches, sundials, and scientific instruments

Life & work

Hans Gruber, also known as Gruwer, was a prominent maker based in Nuremberg who became a master locksmith in 1552.

His extensive production ranged from clocks and watches to astronomical compendia and gunnery instruments, spanning active work between 1565 and 1583. Ten distinct forms of his maker's mark are recognized, frequently featuring his initials HG alongside two crossed spades within a shield. Gruber was also recognized for technical innovations, such as the implementation of a concentric minute hand in his watch designs.

For the adjustment of his sundials to the vertical position, he adopted the needle-level device invented by his fellow citizen Christian Heiden.

The fuller biography summarises the open references listed under Sources; each statement was checked against the cited passage. Confirm key dates in period documents before relying on them.

Training, contributions & innovations

  • He adopted the needle-level, an invention by Christian Heiden, for the purpose of adjusting his sundials to the vertical.
  • His horological work includes early examples of the concentric minute hand mechanism.

Documented works

  • An astrolabe-clock, dated 1550, is held at the Institute for Theoretical Astrophysics at the University of Oslo.
  • A vertical table-clock, dated 1565, is in the collection of the Württembergisches Landesmuseum in Stuttgart.
  • A clock dated 1574 is located within the Kunsthistorisches Museum in Vienna.
  • A chaise-watch is preserved in the Germanisches Nationalmuseum in Nuremberg.

Collecting significance

The catalogued pieces listed on this page show the kinds of objects auction houses, dealers and museums attribute to this maker; each attribution is the source's own.

Firms, key models & movements

Firms

  • Junghans · 1861
  • Rolex · 1905 (as Wilsdorf & Davis in London); the Rolex name registered in 1908
  • Tudor · Not recorded

Key models (as recorded for the firm)

  • Wall and mantel clock movements
  • Kitchen and regulator clocks
  • rolex-calibre-3135
  • Oyster
  • Datejust
  • Submariner

Movements

In the object catalogue

2 catalogued objects are recorded under Grüber, Hans. Attributions are as given by each source and are not independent authentication.

  • The face of the watch, showing the dial, hour hand, and the internal structure of the pierced cover.
  • Sun and moon dial by Hans Gruber, showing the interior dial and the base-mounted compass.

Sources & references

  1. stackfreed watch; quarter-striking watch | British Museum, British Museum, retrieved 2026-11-03 (paraphrased; text © the publisher)
  2. Epact: Scientific Instruments of Medieval and Renaissance Europe, History of Science Museum, Oxford, retrieved 2026-11-03 (paraphrased; text © the publisher)

Where sources disagree, the disagreement is stated rather than resolved silently.