Image: Wikimedia Commons

quadrant

Navigation instrument

EntityQ841280

Subclass of: measuring instrument

Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

A quadrant is an instrument used to measure angles up to 90°. Different versions of this instrument could be used to calculate various readings, such as longitude, latitude, and time of day. It was first proposed by Ptolemy as a better kind of astrolabe. Several different variations of the instrument were later produced by medieval Muslim astronomers. Mural quadrants were important astronomical instruments in 18th-century European observatories, establishing a use for positional astronomy.

Overview

All data

21 statements · 14% with external sources · numbers in brackets are citations

Replaces: astrolabe

On other databases

21 identifiers linking quadrant across the web's reference databases

Data quality

statements

14%

externally sourced

Source last edited July 23, 2026. AIDb refreshes this page daily.

Suggest a fact or correction

Links

Use this data

curl https://aidb.si/api/v1/entities/Q841280

API docs, limits & keys

Cite this page

AIDb. (2026). quadrant (Q841280). Retrieved from https://aidb.si/e/quadrant-Q841280