astrolabe

Everyday

1. An old instrument made of brass discs and a pointer, used to measure how high the Sun or a star is above the horizon. tree →
2. With it, sailors and astronomers could work out the time and where they were on Earth. tree →

In the lessons

In history and science lessons it appears in stories of early astronomers and Islamic and medieval scholars, and in lessons on how people found their way before GPS. It tells the reader the scene is long ago and about stars, time or navigation. Phrases: «a brass astrolabe», «use an astrolabe».

Examples

• The museum had a shiny brass astrolabe in a glass case. tree →
• Sailors once used an astrolabe to find how far north they were. tree →
• The astronomer held up the astrolabe to the night sky. tree →
• Our class made a paper astrolabe in science. tree →
• An astrolabe measures the height of a star above the horizon. tree →
• Scholars in Baghdad improved the astrolabe long ago. tree →
• She turned the ring of the astrolabe to line it up with the Sun. tree →

Note

Countable noun: an astrolabe, two astrolabes. Stress on the first syllable: AS-tro-labe. Not a telescope: it does not make things look bigger, it measures angles. Later sailors used the sextant instead.