Search results
Results from the WOW.Com Content Network
The kamal itself was simple to construct. It was a rectangular piece of either bone or wood which had a string with 9 consecutive knots attached to it. Another instrument available, developed by the Arabs as well, was the quadrant. Also a celestial navigation device, it was originally developed for astronomy and later transitioned to navigation ...
Navigational instruments are instruments used by nautical navigators and pilots as tools of their trade. The purpose of navigation is to ascertain the present position and to determine the speed, direction , etc. to arrive at the port or point of destination.
Early mechanical compasses are referenced in written records of the Chinese, who began using it for navigation "some time before 1050, possibly as early as 850." [ 21 ] [ 10 ] At present, according to Kreutz, scholarly consensus is that the Chinese invention used in navigation pre-dates the first European mention of a compass by 150 years. [ 22 ]
A simple wooden kamal. A kamal, often called simply khashaba (wood in Arabic), [1] is a celestial navigation device that determines latitude.The invention of the kamal allowed for the earliest known latitude sailing, [2] and was thus the earliest step towards the use of quantitative methods in navigation. [3]
A marine chronometer is a precision timepiece that is carried on a ship and employed in the determination of the ship's position by celestial navigation.It is used to determine longitude by comparing Greenwich Mean Time (GMT), and the time at the current location found from observations of celestial bodies.
Three Mariner's Astrolabes in the Museum of the Forte da Ponta da Bandeira; Lagos, Portugal. The mariner's astrolabe, also called sea astrolabe, was an inclinometer used to determine the latitude of a ship at sea by measuring the sun's noon altitude (declination) or the meridian altitude of a star of known declination.
The frame of a sextant is in the shape of a sector which is approximately 1 ⁄ 6 of a circle (60°), [2] hence its name (sextāns, sextantis is the Latin word for "one sixth"). "). Both smaller and larger instruments are (or were) in use: the octant, quintant (or pentant) and the (doubly reflecting) quadrant [3] span sectors of approximately 1 ⁄ 8 of a circle (45°), 1 ⁄ 5 of a circle (72 ...
The instrument was discussed in all navigation manuals beginning in the mid-16th through the 17th century; it lost its prominent place in celestial navigation when the cross staff and the Davis quadrant gained general acceptance. According to a census of 2018 more than 100 astrolabes are preserved, most of them salvaged from wrecks.