Noun
marine chronometer (plural marine chronometers)
A timepiece used as a portable time standard at sea so as to enable the determining of longitude by means of celestial navigation.
A nautical almanac and a marine chronometer are used to compute the subpoint on earth a celestial body is over, and a sextant is used to measure the body's angular height above the horizon. Source: Internet
John Harrison created the first highly accurate marine chronometer in the mid-18th century. Source: Internet
Scientific heritage John Harrison of Barrow upon Humber (but born in Yorkshire at Foulby ), invented the marine chronometer which allowed longitude to be accurately measured, and hence navigation at sea. Source: Internet
Though the Board of Longitude rewarded John Harrison for his marine chronometer in 1773, chronometers remained very expensive and the lunar distance method continued to be used for decades. Source: Internet
Only in the middle of the 18th century, after the marine chronometer was invented and the spatial distribution of magnetic declination was known, could the Mercator projection be fully adopted by navigators. Source: Internet
The book remains the authoritative work on the marine chronometer. Source: Internet