Possessives

• mariner: For navigational purposes a more basic and sturdy version was needed, and this became known as the mariner's astrolabe.

Converse of object

• include: The ticket counter is in a lobby, where there is a bust of Halley and some instruments, including a 1580 astrolabe.

• make: Activities include making a simple astrolabe, calculating your moon weight and writing a letter to an alien.

• invent: Sharaf al-Din al-Tusi ( born 1201 ) invented the linear astrolabe.

Adjective modifier

• astronomical: Beside their use for determining astronomical events astrolabes were used as teaching tools in the late Middle Ages.

• linear: Sharaf al-Din al-Tusi ( born 1201 ) invented the linear astrolabe.

• European: Bookmark: Sloane Astrolabe An adaptation of the earliest known European astrolabe, from England, around AD 1300.