The next item in the series is a large cog which was attached to the first Wanganui Town Bridge. Measuring 110 cm across the base and 180 cm high, it is part of the turning mechanism that allowed a section of the bridge to swing open and let ships through.
A swing span was a common feature of early bridges in New Zealand when shipping was still the best form of transportation of goods and people. Once the span opened, the ships would sail up to the sheltered basin near Shakespeare Bluff to discharge cargo.
Although not built until 1871, the structure had been in development since 1857 when a petition requesting a bridge was submitted to the Provincial Superintendent.
The first pile was driven into the riverbed in 1859, but the project met continuous halts due to failed contracts and arguments over the location.
The turbulence of the 1860s also halted work on the bridge, with fraught land purchases and the resulting wars causing tension and bringing threats to the area. Despite not having a permanent bridge, Whanganui was a prime transport location and became a major military site during this time.
As the region began to calm and peace was resuming, the bridge project was raised again. A plan by Mr Henry McNeil was accepted at a cost of £30,000, around four million dollars in today's money. The bridge was formally opened by Governor Sir George Ferguson Bowen on 28 November 1871.
Tolls were introduced to help pay for the bridge: A penny for pedestrians, sixpence for horseback riders, nine pence for two-wheeled carriages with springs and a shilling for those without and two shillings for four-wheeled carriages.
Stock were charged by the head. The first toll was paid by pedestrian Mr George Ross. Mr Tom Jones was the first to cross on horseback, riding backwards for the occasion.
Prior to construction, all people, stock and goods were transferred across the river by small boats or by pulley bridges, but a permanent bridge made access much easier.
After it opened, the bridge became the main link between the coast and the hinterland, and the port boomed with the increased ease of access to trade routes.
Coaches had already made their way north but the bridge helped to open up transport routes to Whangaehu, Turakina, Marton, Bulls and Palmerston North.
These routes from town to town spurred the development of rural roads, and more farms became established. A significant proportion of the Whanganui economy came from this fertile farming hinterland.
Whanganui became New Zealand's second most important town and port. The European population advanced at a great rate and by 1886 was around 15,000. At the same time, the Māori population was 1,770, having halved within 15 years.
As technology developed, gas and water pipes and telephone lines were fitted to the bridge but these proved to be cumbersome as they had to be disconnected every time the span opened, resulting in a half hour delay for those waiting to cross.
The span last opened in 1902 when the SS Huia passed through carrying materials to fix the Aramoho Rail Bridge which had opened in 1877. In 1914 the span on the Town Bridge was closed up permanently, meaning it was no longer a swinging structure. It was finally demolished in 1969.
Sandi Black is the archivist at Whanganui Regional Museum.