The sextant is an instrument that lets you know where you are by determining the sun’s location in the sky – how far above the horizon and how far north or south in the sky.
Essentially the same instrument has been used to pinpoint the exact locations of stars in the sky, enabling astronomers to create very accurate charts of what’s up there at night.
The sextant descended from the octant, which descended from the backstaff, which descended from one of my favorite astronomical instruments of all, the cross staff, which is basically a stick with a piece of wood that slides on it.
Yeah, two sticks. You can learn a lot from them.