Science: Deserted Meridian

The earth’s astronomical navel* was about to shift its position. Britain’s Royal Observatory was preparing for its first permanent move in 271 years. Left behind in Greenwich (now part of London) would be 1) the original building designed by Sir Christopher Wren, and 2) the “prime meridian of longitude,” which passes through the observatory grounds. The “Meridian of Greenwich” could not be moved; every modern map in the world had been drawn with it as a base line.

In 1675, Charles II, the “Merry Monarch,” tore himself away from his mistresses long enough to consider the stars. They must be, he decided, “anew observed, examined and corrected, for the use of his seamen.” Forthwith he commanded “our trusty and well-beloved Sir Christopher Wren, Knight” to build “a small observatory within our park at Greenwich . . . with all convenient speed.” Those were bargain days. Sir Christopher tore down a gatehouse in the Tower of London and a fort at Tilbury. With the salvaged stone and timber, and with £520 from the sale of old gunpowder, he ran up a building on a grassy bank of the Thames, well out in the country where the sky was as apt to be clear as average English sky. It was designed, he explained, “for the observer’s habitation and a little for pompe.”

Greenwich Time. Ships visiting London used to send their chronometers to Greenwich to be set by telescopic observation of the stars. After 1833, their officers watched a 5-ft. ball on a pole above Sir Christopher’s building. When it dropped, the “Greenwich time” was 1 p.m. The custom led, in 1884, to an international agreement fixing the meridian of Greenwich as “zero longitude.” The maps of the world still use this north-and-south line as a starting point. The world’s clocks are still set by reference to its time.

But time, in other respects, was not kind to Greenwich. Like an ugly fungus, London crept around King Charles’s royal park. The city’s smoke blinded the telescopes, corroded metal parts, covered lenses with soot. Electric railways interfered with magnetic observations. Worst were street lights, whose glare outshone the Milky Way. Only British astronomers could have hung on so long.

Traditionalists among them had little need to mourn. The observatory’s new home will be older than its old one: Hurstmonceux (pronounced herst-mon-syoo) Castle in Sussex, built in 1446. From its grounds new and old telescopes will observe the smokeless sky.

The present Astronomer Royal, Sir Harold Specer Jones, will live in the castle itself, with two resident ghosts. Sir Harold and his staff are practical modern scientists. Routine haunting they will ignore. But the first ghost who monkeys with “Greenwich Mean Time,” they declared last week, will be scientifically exorcised.

*Like those of Adam & Eve, an arbitrary point, not bestowed by nature.