Un sestante misura gli angoli in mare

A Sextant Measures Angles at Sea

A sextant is a navigation instrument that measures angles. Its unusual shape helps us see how sailors could use careful measurement at sea. Instead of looking like a modern screen or compass, it has a large curved scale, a moving arm, and small optical parts. To use a sextant, a navigator looks through its optical system and measures the angle between a point in the sky and the horizon. This angle can help with navigation and with finding a ship’s position. The tool does not simply show a place. The navigator must read the scale and use the measurement carefully. The image shows a dark triangular frame. A long golden arm crosses the open center. At the bottom, a wide curved scale carries many small marks. Round parts near the top are part of the optical system. A thin wire hangs from one side. A sextant is interesting because a simple angle can provide useful information during a sea journey.