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The sextant is a precision navigational instrument used primarily at sea to measure the angle between two visible objects, most commonly the horizon and a celestial body (like the Sun, Moon, or stars). This measurement is essential for determining a ship's latitude and longitude, helping navigators fix their position accurately.
🔧 Key Features:
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Measures angles up to 120°, despite its name (from "sextans", Latin for one-sixth of a circle or 60°).
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Consists of a graduated arc, index mirror, horizon mirror, telescope, index arm, and filters.
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Works using the principle of double reflection to bring two images into alignment.
📌 How It Works:
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The observer looks at the horizon through the horizon mirror.
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The index arm is moved until the celestial object appears to sit on the horizon.
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The angle on the arc is read, indicating the object's altitude above the horizon.
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Combined with time and nautical almanacs, this angle helps calculate the position of the ship.
🧭 Importance in Navigation:
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Critical in celestial navigation, especially before the era of GPS.
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Still used today as a backup navigation tool.
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Enhances understanding of traditional seamanship.
🛠️ Applications:
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Marine and air navigation
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Educational training in maritime academies
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Emergency navigation
