Skip to content
Home
People
Places
Science
History
Culture
More
▾
Science & Space
Space
Technology
Natural World
Historical Figures
Inventions
Discoveries
Geography
ع
文A
Home
›
H4
H
Object
H4
1 article
7 relations
Articles about H4
Marine Chronometer
A marine chronometer is a precision timekeeper accurate enough to be used as a portable reference for finding longitude at sea. The problem was urgent by the early eighteenth century, and in 1714 the British Parliament offered a £ 20,000 reward for a practical…
Relationship graph
J
Jamaica
explored by
›
J
John Harrison
built by
›
J
John Harrison
developed by
›
J
James Cook
explored by
›
J
John Jefferys
developed by
›
L
Larcum Kendall
built by
›
l
longitude
part of
›
Explore related
J
John Harrison
Person
2
B
Board of Longitude
Institution
2
H
H1
Object
2
H
H3
Object
2
J
John Arnold
Person
2
J
James Cook
Person
1
J
Jamaica
Place
1
G
Greenwich
Place
1