Lectures in Navigation

Lectures in Navigation is a text book prepared by Lieutenant Ernest G. Draper for use at the Officers' Material School of the Naval Auxiliary Reserve. The foreword says the lectures were compiled as speedily as possible to meet the demand for some quick but fairly comprehensive method whereby large bodies of men, divided into small classes, might learn the elements of navigation.

The text shows how to identify and name any point or quarter-point on the compass card and furnishes a guide for changing a point course into a degree course, for either new or old compass. The notes explain that there are 60' in each degree, and give four degrees, ten minutes and thirty seconds as the example of how an angle is written. Another section explains that a position worked out from an altitude of the sun taken by sextant lies on a little arc which, for all purposes in Navigation, is a straight line at right angles to the true bearing of the sun. One exercise describes a ship that at midnight ran into dense fog and slowed down to 8 knots, and gives an observed altitude of Star Polaris.