English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Longitude determination at sea gained increasing commercial importance in thelate Middle Ages, spawned by a commensurate increase in long-distance merchantshipping activity. Prior to the successful development of an accurate marinetimepiece in the late-eighteenth century, marine navigators reliedpredominantly on the Moon for their time and longitude determinations. Lunareclipses had been used for relative position determinations since Antiquity,but their rare occurrences precludes their routine use as reliable way markers.Measuring lunar distances, using the projected positions on the sky of the Moonand bright reference objects--the Sun or one or more bright stars--became themethod of choice. It gained in profile and importance through the British Boardof Longitude's endorsement in 1765 of the establishment of a Nautical Almanac.Numerous 'projectors' jumped onto the bandwagon, leading to a proliferation oflunar ephemeris tables. Chronometers became both more affordable and morecommonplace by the mid-nineteenth century, signaling the beginning of the endfor the lunar distance method as a means to determine one's longitude at sea.

A (not so) brief history of lunar distances: Lunar longitude determination at sea before the chronometer