How to Find a Latitude Using Polaris

Making Your Sextant

• 1

  Tape the straw securely along the side of the protractor, centering it along the 90-degree mark on the curved side and the center mark on the straight edge.

• 2

  Tape one end of the string to the opposite side of the protractor, aligning it with the center mark on the straight edge. When the straw is held parallel to the ground, the string should pass through the 0 degree mark.

• 3

  Cut the string off so that it hangs 5 or 6 inches past the bottom of the protractor. Tie a small weight to the end to keep the string taut. A large paper clip works well for this purpose.

Measuring Your Latitude

• 4

  Locate Polaris in the sky. Polaris is a bright star forming the end of the handle of the Little Dipper. If you draw an imaginary line passing through the two stars at the bottom of the Big Dipper, that line will pass through Polaris.

• 5

  Point the straw of your sextant at Polaris with the straight edge of the protractor pointing away from you. Sight through the straw until Polaris is visible through it.

• 6

  Hold your sextant steady and vertical until the string stops swinging. Press the string against the protractor and see what degree measurement it passes through. Note this measurement.

• 7

  Take two more measurements of Polaris for better accuracy. Use the average of the three measurements for your latitude.