cross-staff
Medieval angle measuring device
A cross-staff is a navigational instrument used from medieval times through the 17th century to measure the angle between the horizon and a celestial body, helping sailors determine latitude.
It consists of a long staff with a sliding crosspiece held up to the eye: The navigator raised his cross-staff to sight the North Star.
Also called a Jacob's staff.
Ancient altitude-measuring instrument
- quadrantFourth of a circle
- sextantMaritime angular measurement device
- latitudeGeographic or personal freedom
- altitudeMeasured height above reference
horizon · mariner · celestial · transom · sailing · longitude · cartography · Ptolemy
astrolabe
Ancient altitude-measuring instrument
- quadrantFourth of a circle
- sextantMaritime angular measurement device
- latitudeGeographic or personal freedom
altitude · horizon · mariner · celestial · transom · sailing · longitude · cartography · Ptolemy · exploration
theodolite
Precision angle-measuring instrument
altitude · azimuth · triangulation · baseline · leveling · rod · plumb · angle · measurement · elevation
polyphony
Simultaneous independent melodic lines
- counterpointSimultaneous independent melodies
- textureSurface tactile quality
- harmonyAgreement or musical blend
voices · fugue · canon · imitation · soprano · alto · tenor · bass · chorale · motet
- measuring toolstape measure, ruler, yardstick, tablespoon, teaspoon
- antique instrumentsastrolabe, sextant, octant, quadrant, theodolite
- navigation aidscompass, maps, road signs, signs, GPS
- maps and globesglobe, world map, celestial globe, terrestrial globe, star map
- navigationcompass, compass rose, signs, charts, navbar
- ancient calculatorsabacus, tally stick, quipu, slide rule
cross-staffGPS
Satellite-based location technology
satellite navigation · sextant · octant · astrolabe · quadrant
cross-staffcompass
Device showing cardinal directions
magnetic compass · mariner's compass · gyrocompass · dead reckoning · lodestone
cross, staff, crosses, crossed, crossing, crosser, staffs, staffed, staffing