Why a ball? Why do people cram themselves into Times Square in New York City every New Year's Eve to watch a ball slide down a pole? Why don't they watch the hands of a giant clock, or sand slipping through a mammoth hourglass?
The answer is "because of public time." New Year's Eve is our celebration of public time, the act of living our lives according to a common standard of minutes, seconds, and hours. We watch the year change at a common instant, at a time accepted by all. And the oldest mechanical symbol of such public time is not the clock or even the hourglass, but the time ball.
Reasonably accurate spring-driven clocks - the so-called balance spring clock that ticks and tocks - appeared about 1675. But they did not immediately give people the sense of common time. These clocks, though vast improvements over earlier technology, were not the best timekeepers. Some ran fast, some ran slow, and all were affected by temperature and humidity.
To have a public sense of time, we needed to synchronize our clocks. The people who most needed to have an accurate sense of time were ship captains.
In the days before global positioning systems, navigators tracked their ships' positions using a good clock and the position of the sun and stars. Determining a ship's latitude (how far north or south it was) could be as simple as finding the angle of the sun at noon. But to find one's longitude (how far east or west), you needed to know the time.
Nautical almanacs contained tables indicating when the sun would set, the moon would rise, and the stars would appear overhead on a particular day. These almanacs were prepared by observatories, such as the Royal Observatory at Greenwich, England, the Paris Observatory, or the United States Naval Observatory in Washington, D.C.
To use these almanacs, a navigator needed to know - as accurately as possible -what time it was at the observatory that had produced the almanac. By knowing when such events would occur at the observatory, and knowing what time the events occurred at one's present location (one could determine local time by observing solar noon), you could find your longitude. To help navigators know the time, observatories and ports began using time balls.
Ports placed time balls in places where they could be seen by ships waiting to depart. In New York, the time ball was placed atop the Custom House. In San Francisco, the ball was mounted on Telegraph Hill. Shortly before noon, the keepers of these balls would raise them to the top of their staffs. At the stroke of noon, the balls would drop down the pole and all the navigators would adjust their clocks to show noon.
Time balls first appeared about 1833 and were used throughout the 19th century. Why not shoot a cannon instead? The sound of a cannon travels slowly through the air and can echo off hills and buildings. An unfavorable wind could make a cannon report inaudible.
Time balls became an official way of announcing time and were installed on buildings with no connection to a port. By 1884, the year the Western nations accepted Greenwich Mean Time as their standard time, the United States government had installed a time ball on the State, War, and Navy Building next to the White House, far from any port.
The time ball in Times Square was never used to announce noon to the boats in New York Harbor. It was first installed in 1907 and has only been used to mark special occasions. The ball this year is new and made of Waterford crystal.
When it falls, it will not be announcing the time to ships at sea. Instead, it will be telling an ocean of humanity to change its calendars in a common instant.
(c) Copyright 1999. The Christian Science Publishing Society