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Theodolite
How It Works
This instrument is used to determine the exact position of a star in the night sky. At first the arrow with “N” written on it is pointed towards the north. Then the green box is rotated so that it remains in the same direction as the star. Then we have to look at the star through the pink straw attached to the protractor. Then the angle on the protractor and that on the base are noted. Thus we get the exact position of the star and can look at the same star next day by pointing to the same direction.