Sextants
Celestial navigation is probably the oldest method of determining position without landmarks. Over the centuries, remarkable methods and precision instruments have been developed for this purpose. The last mechanical instrument still used today is the sextant or drum sextant. In astronavigation, the sextant determines the vertical angle between a celestial body and the horizon. For coastal navigation it can also be used horizontally, e.g. to measure the distance from several landmarks. The micrometre drum represents the latest refinement of modern drum-type …









































