backstaff Definition
an instrument formerly used in navigation for measuring the altitude of a celestial body, typically consisting of a graduated arc with a pivoted pointer at one end and two sights at the other, one of which was fitted with a small mirror.
Using backstaff: Examples
Take a moment to familiarize yourself with how "backstaff" can be used in various situations through the following examples!
Example
The backstaff was used by sailors to measure the altitude of the sun or stars.
Example
The backstaff was invented in the early 16th century.
Example
The backstaff was replaced by the octant in the 18th century.
backstaff Synonyms and Antonyms
Synonyms for backstaff
- Davis quadrant
- reflecting quadrant
Phrases with backstaff
Example
The navigator took the sun with a backstaff to determine their position.
Example
Sailors would use a backstaff to navigate the seas.
the process of taking a measurement of the altitude of a celestial body using a backstaff
Example
The captain ordered a backstaff observation to determine their location.
Origins of backstaff
from 'back' + 'staff', referring to the method of use where the observer stands with his back to the sun and holds the instrument vertically in front of him
Summary: backstaff in Brief
'Backstaff' [ˈbakstɑːf] is an old navigation tool used to measure the altitude of a celestial body. It consists of a graduated arc with a pivoted pointer and two sights, one of which has a small mirror. Sailors would use it to navigate the seas, and it was replaced by the octant in the 18th century. Phrases include 'take the sun with a backstaff,' 'use a backstaff,' and 'backstaff observation.'
