Zero Degrees: Geographies of the Prime Meridian

Research output: Book/ReportBook


Space and time on earth are regulated by the prime meridian, 0°, which is, by convention, based at the Royal Observatory, Greenwich. But the meridian’s location in southeast London is not a simple legacy of Britain’s imperial past. Before the nineteenth century, more than twenty-five different prime meridians were in use around the world, including Paris, Beijing, Greenwich, Washington, and the location traditional in Europe since Ptolemy, the Canary Islands. Charles Withers explains how the choice of Greenwich to mark 0° longitude solved complex problems of global measurement that had engaged geographers, astronomers,and mariners since ancient times.

Withers guides readers through the navigation and astronomy associated with diverse meridians and explains the problems that these cartographic lines both solved and created. He shows that as science and commerce became more global and as railway and telegraph networks tied the world closer together, the multiplicity of prime meridians led to ever greater confusion in the coordination of time and the geographical division of space. After a series of international scientific meetings, notably the 1884 International Meridian Conference in Washington, DC, Greenwich emerged as the most pragmatic choice for a global prime meridian, though not unanimously or without acrimony. Even after 1884, other prime meridians remained in use for decades.
Original languageEnglish
Place of PublicationHarvard and London
PublisherHarvard University Press
Number of pages326
ISBN (Electronic)2016040039
ISBN (Print)9780674088818
Publication statusPublished - 17 Mar 2017


Dive into the research topics of 'Zero Degrees: Geographies of the Prime Meridian'. Together they form a unique fingerprint.

Cite this