Navigation by the North Star

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Concerning the North Star, and its uses and limitations.

The North Star

It is said by many sailors that the North Star is always to be found due North, but this is not true as any real Mariner shall tell you, and the proof of this is to be found when on land or moored, on a clear night. For like all starts and Celestial bodies, the North Star moves through the sky around the Celestial Pole, and its position shall vary by a full 3 ½° either side of North, or 7° in all. Yet it is still of use to the informed, for it is a clear and bright Star of the first magnitude which is easily found, and from the declination or Altitude of the North Star you can immediately learn your true Latitude, and from its direction your course or way.

The Wains and Guards

Near the North Star are several distinctive stars of the second and third magnitude, the closest pair being the Wains, and around them the Guards. The Wains are to be found on the further side of the North Pole from the North Star. To find the Pole, draw a line between the North Star and either of the Wains, wherein the Pole is to be found close to this line and a third of the way along. Being that the Wains are a full point from the North Star, so the North Star is almost a third of a point, or 3°30' from the North Pole, in almost the opposite direction from the Wains. But when taking a bearing or declination on the deck of a ship at sea, it is not wise to judge the third of a distance between two Stars, it being better to instead take the measure of a Star, and then to adjust it as necessary. So must we provide the rule for adjusting the position of the North Star to find the North Pole.

The Capital Points

1. If the Wains are above the North Star, then the North Star is 3° below the North Pole and 1°30' to the left.
2. If the Wains are above and to the right of the North Star, then the North Star is 3°30' below the North Pole and is 30' to the left.
3. If the Wains are to the right of the North Star, then the North Star is 1°30' below the North Pole and 3° to the left.
4. If the Wains are below and to the right of the North Star, then the North Star is 30' above the North Pole and is 3°30' to the left.
5. If the Wains are below the North Star, then the North Star is 3° above the North Pole and 1°30' to the right.
6. If the Wains are below and to the left of the North Star, then the North Star is 3°30' above the North Pole and is 30' to the right.
7. If the Wains are to the left of the North Star, then the North Star is 1°30' above the North Pole and 3° to the right.
8. If the Wains are above and to the left of the North Star, then the North Star is 30' below the North Pole and is 3°30' to the right.