Skip to content
The Encyclopedia of Horology

Florence, Italy · Dates not established

Giovanni Battista Giusti

Partially verified

Maker of astronomical and time-measuring instruments

Life & work

Giovanni Battista Giusti was a prominent artisan working in Tuscany during the second half of the 16th century.

He operated a workshop in Florence that produced high-quality scientific instruments, including horary quadrants and other specialized astronomical devices. His instruments were frequently calibrated for the latitude of Florence and occasionally featured dedications to influential patrons such as Cosimo I de' Medici.

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.

Documented works

  • A horary quadrant by Giusti, featuring a degree scale and Italian hour lines, is preserved in the collections of the Museo Galileo.
  • Another quadrant signed by the maker displays a perpetual calendar on its reverse and is held within the Museo Galileo.

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

No firm, model or movement in this encyclopedia is yet recorded under this maker's name.

In the object catalogue

4 catalogued objects are recorded under Giovanni Battista Giusti. Attributions are as given by each source and are not independent authentication.

  • Front face of the Giovanni Battista Giusti quadrant dated 1568.
  • Gilt brass quadrant with open scaphe sundial cover and original case in the background.
  • The obverse face of the brass quadrant, showing the Italian hour dial, zodiacal calendar, shadow square, and the signature of Giovanni Battista Giusti.
  • A 16th-century brass declinatory quadrant with an alidade and integrated compass.

Sources & references

  1. Museo Galileo - Horary quadrant, Museo Galileo, retrieved 2026-11-03 (paraphrased; text © the publisher)
  2. Museo Galileo - Quadrant, Museo Galileo, retrieved 2026-11-03 (paraphrased; text © the publisher)
  3. Museo Galileo - Quadrante orario, Museo Galileo, retrieved 2026-11-03 (paraphrased; text © the publisher)
  4. Museo Galileo - Section of Room II - Italian Makers of Astronomical Instruments, Museo Galileo, retrieved 2026-11-03 (paraphrased; text © the publisher)
  5. Collections, museogalileo.it, retrieved 2026-11-03 (paraphrased; text © the publisher)
  6. Museo Galileo - Astrolabe, Museo Galileo, retrieved 2026-11-03 (paraphrased; text © the publisher)

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