Possible Clues:

• Old navigation instrument
• A sort able to produce old instrument
• Early astronomical instrument
• Old instrument used to measure altitude of stars and planets
• 'A stroll, by the sound of it, with Abraham will help with the navigation (9)'
• A brief walk with a live navigational device
• Old astronomical instrument
• Astronomical instrument of former times
• Old instrument that's broken in a lab store
• At last a bore of old for bearings