The invention of the magnetic compass, telescope and sextant enabled increasing accuracy. Deblois made his way to the cabin, where he seized a sextant, chronometer and chart. He holds patents for a geodetic instrument and an electronic sextant. Navigational sciences were highly developed, making use of a rudimentary sextant (known as a kamal). The sextant, developed in the 18th century, made more accurate charting of nautical position possible. He began manufacturing Hadley's quadrant (a predecessor to the sextant) and optical instruments. Brahe then created the Triangular Sextant in 1582. The sextant, an optical instrument, is used to perform this function. The purpose of the Fakhri sextant was to measure the transit altitudes of the stars. The aeronautical sextant was introduced in 1922. Byrd took a sextant reading of the Sun at 7&colon;07&colon;10 GCT. James gives him a uniform and Baines gives him a sextant. The Sextant reading is known as the 'Sextant Altitude'. In 1757, John Bird invented the first sextant. For this contract, Elbit was chosen over GEC-Marconi and Sextant Avionique.