Sextant with artificial horizon (Gago Coutinho)
Sextante con horizonte artificial (Gago Coutinho)
- Date
- 1921 · confidence medium
- Place
- Lisbon, Portugal
- Credited to
- Gago Coutinho
- Field
- Movement
⚠️ Disputed: the sources disagree.
What it is
An adaptation of the marine sextant with two spirit levels that provide an artificial horizon for measuring the altitude of celestial bodies without a visible horizon, essential for navigating by aeroplane over the sea. With it, Gago Coutinho and Sacadura Cabral crossed the South Atlantic in 1922 from Lisbon to Rio de Janeiro.
Others designed bubble sextants in the 1910s-1920s (in the United Kingdom and the United States); priority among these independent designs is unclear. Gago Coutinho's contribution is his version for the 1922 flight.
What it led to
- the first aerial crossing of the South Atlantic (1922)
- celestial navigation in flight
- bubble sextants used in aviation until the era of radio and GPS