At two minutes to one, it rises all the way to the top.
At exactly one PM, the ball falls with a dull thud.
The church clocks were not very accurate but most people had no need for precise time.
The time ball atop Flamsteed House at Greenwich, London.
Photo credit:Carmen Seaby/Flickr
Things were different for a ships captain.
But Harrisons remarkable invention was still useless if it couldnt be set correctly before departing on a long voyage.
The idea of the time ball was proposed in 1829 by Robert Wauchope, a Royal Navy captain.
Sailors could view it through a telescope and set their chronometers accordingly.
A visual signal rather than an audial one, as in church bells, was also advantageous.
Sound travels slow through the air, taking about three seconds to cover a kilometer.
Wind, rain, humidity and other atmospheric conditions also affect the speed of sound.
Relying on sound signals to tell time was inherently flawed.
The Greenwich Time Ball.
Photo credit:David Brossard/Flickr
The first time ball was erected in the harbor at Portsmouth, England.
There are over sixty time balls standing at harbors around the world today.
The Greenwich Time Ball.
Photo credit:Duncan Stephen/Flickr
The Greenwich Time Ball.
Photo credit:www.rmg.co.uk
The Boston Time Ball on the roof of the Equitable Life Assurance Society building.
Photo credit:Winslow Upton and William Babcock Hazen/Public domain
Williamstown Lighthouse and Time Ball Tower, Australia.
Photo credit:VICPhotoSurvey/Panoramio
Time ball atop the Old Windmill in Wickham Park, Brisbane, Queensland, Australia.
Photo credit:Andy Mitchell/Flickr
Time ball on Clock Tower, Brighton.
Photo credit:AKS.9955/Wikimedia
Nelson Monument, in Edinburgh, Scotland has a time ball installed in 1853.
Photo credit:Jay Hogan/Flickr
A time ball at Sydney Observatory, Sydney, Australia.
Photo credit:Greg O’Beirne/Wikimedia
Time Ball Tower, Portswood Ridge, Victoria and Alfred Waterfront, Cape Town.
Photo credit:gigi_nyc/Flickr
Sources:NY Times/The Greenwich Phantom/Wikipedia/Royal Museums Greenwich
