But why was the Timeball built in the first place? In pre-GPS days, longitudinal position at sea was calculated by comparing local time against Greenwich mean time, as measured by the ship’s chronometer. An error in the timepiece of four seconds translated to 1800 metres of distance at the equator, so precision was vital. By sighting a timeball dropped at known Greenwich time, a navigator could ensure the accuracy of their chronometer to the second.

In the latter part of the 19^th Century, any port worth its salt had a timeball – in Aotearoa New Zealand that included Auckland, Wellington and Dunedin – although in many cases they were incorporated in existing structures. The Canterbury Provincial Council went one better, commissioning architect Thomas Cane to design a 10.4 metre octagonal tower for the timeball and an adjoining station for the astronomical clock and to accommodate a keeper and family.

Built from local scoria complemented by lighter Oamaru stone, Cane’s complex has been described as a “castellated confection” atop Officers’ Point. The original timeball and apparatus was from Siemens Bros of Germany; the astronomical clock, which was calibrated with the Colonial Observatory at Wellington via the Lyttleton Post Office, was supplied by E Dent & Co of London, makers of London’s famous Big Ben clock. A nearby flagpole enabled the keeper to communicate by flag with ships arriving at the heads and to relay information to and from the port.

It's a steep walk to reach the site so allow plenty of time. Today when you visit the timeball, only the restored timeball and tower remain, with the footprint of the station building left as a reminder of what once stood on the grounds. From the tower grounds you can see all the way to the heads and across to Diamond Harbour, so enjoy the view while you’re waiting. At 12.58 the timeball will rise to half-mast, the traditional ‘heads-up’ to ships in the harbour that the drop was imminent.

Afterwards, head over for a stroll through Urumau Reserve, the 26-hectare reserve behind the Timeball tower on Lyttelton’s flank. If you’re fit, there’s a great short walk up to and along the Crater Rim walkway, with the option of taking the historic Bridle Path back down to Lyttelton. Lyttelton township is a listed historic area and well worth exploring. Around town, the remains of Lyttelton Gaol are worth a look (up some stairs off Oxford St), as is 1851 Grubb cottage. If you’re visiting on a Saturday morning, spend time exploring the excellent Lyttelton Farmers Market followed by a hot drink at one of the local eateries on London Street. From the port, you can take a 10-minute water taxi across to Diamond Harbour and visit the site of historic Godley House, or jump aboard a Black Cat Cruises ferry to Ōtamahua/Quail Island. A former quarantine station and leper colony, it’s now a DOC-administered recreation reserve with a good swimming beach, island circuit walk and a well-stocked ‘ship’s graveyard’ immediately offshore.