[DOC] [TLE] Sextant - Wikipedia [PAR] A sextant is a doubly reflecting navigation instrument used to measure the angle 
between any ... The angle, and the time when it was measured, can be used to 
calculate a ... Both smaller and larger instruments are (or were) in use: the octant, 
quintant (or .... To check for this you need to observe two stars 90 or more apart. [DOC] [TLE] Celestial navigation - Wikipedia [PAR] Celestial navigation, also known as astronavigation, is the ancient art and 
science of position ... The latitude and longitude of that point is known as the 
celestial body's ... that the observer know exact Greenwich Mean Time (GMT) at 
the moment of his ... The sextant and octant are most accurate because they 
measure angles... [DOC] [TLE] Free Flashcards about WEIGHTS & MEASURES - StudyStack [PAR] TO FIGURE OUT YOUR LATITUDE YOU NEED THE EXACT TIME AND THIS 
INSTRUMENT THAT REPLACED THE OCTANT, SEXTANT. IT'S THE TERM FOR
... [DOC] [TLE] Mariners Weather Log Vol. 52, No. 2, August 2008 [PAR] May 15, 2015 ... Here we follow the time line of navigational tools from ancient times into the 19th 
century. ... As the leadsman retrieved the line, he'd call out the depth. .... to use 
the instrument; you do need a clear horizon when measuring ... For many years, 
sailors could find their latitude with the use of celestial navigation. [DOC] [TLE] The History of the Sextant [PAR] So what do navigators need to find their position on the earth's surface by ... 
navigators need an angle-measuring instrument, a sextant, to measure the angle 
of the ... At the equator, which is zero degrees latitude, Polaris is on the horizon 
with zero ... In ancient times, the navigator who was planning to sail out of sight of 
land... [DOC] [TLE] Sailing by Starlight: the lost art of celestial navigation | Southern ... [PAR] Sep 27, 2010 ... As some of you know, I like to build things, and I recently decided to build some 
classic ... If you replace your Latitude Hook with a ruler, you can use it to calculate 
your ... Octants and Sextants use a series of mirrors to correct for ocular ... all you 
need to do is determine the time the sun peaks at your location. [DOC] [TLE] This instrument is really a reproduction of an Octant of the mid 17th ... [PAR] See more about The Mid, Instruments and 17th Century. ... or the sun, the Octant 
allows navigants to determine geographic latitude. ...... A nocturnal is an 
instrument used to determine the local time based on the ... We have the tools 
you need! ..... Sailors used this tool in order to figure out their longititude and 
latitude and... [DOC] [TLE] Navigation - Sextant [PAR] The major problem with back-sight instruments was that it was difficult if not ... the 
angle between the moon and a celestial body, calculate the time at which the 
moon ... Knowing the correct time, the navigator could now determine longitude. 
... The problem of finding your location when you can't see the horizon to take a 
sun... [DOC] [TLE] sextant | instrument | Britannica.com [PAR] Sextant, instrument for determining the angle between the horizon and a celestial 
body such as the ... Octants, with 45 arcs, were first used to calculate latitude. [DOC] [TLE] A Brief History of Navigational Instruments - TechnologyUK [PAR] If a ship was out of sight of land and beset by adverse weather conditions, ..... The 
development of the sextant as a replacement for the octant is largely due to the ... 
In order to be able to calculate your exact position on the Earth's surface, you ... 
the observer need only determine the difference between the time in Greenwich... [DOC] [TLE] DIY: Measuring Latitude and Longitude - OpenLearn - Open University [PAR] It's possible to measure latitude by comparing your position on Earth with the ... 
Unfortunately, this reading is only correct on 21 March and 21 September (the 
spring ... To calculate your longitude, you therefore simply need to work out the 
time ... designated 'the meridian passing through the centre

Question: To figure out your latitude you need the exact time & this instrument that replaced the octant
Answer: a sextant