1
In principle, quadrant and astrolabe are easy to use to establish latitude.
2
When I first navigated it was with an astrolabe and the moon.
3
The compass and the astrolabe-aninstrument for reckoning latitude-hadbeen already invented.
4
The now indispensable sextant was but clumsily anticipated by the newly invented astrolabe.
5
This man used words as a master mariner would use compass and astrolabe.