What do we know about it?
Fragment of an iron fireback from Fernhurst Furnace
This scrap of old iron has much to tell us about one of Chichester District's most important historic industries. It was found in a drainage gully during the 1992 excavation of Fernhurst Furnace.
The Iron Industry of the Weald
The story begins in King Henry VIII's time, when demand for iron, especially for the military, brought the introduction of the blast furnace from northern France. The iron industry in the Weald grew rapidly - by 1600 over a hundred sites were operating. At first their main product was bar iron for sale to blacksmiths, but as Swedish competition grew, so did a new market in iron guns for the Royal Navy.
Iron ore was smelted in a blast furnace to produce cast iron, and then refined in a forge to produce malleable wrought iron.
How the furnace worked
Iron smelting needed three things:
- Iron ore ('mine'), found in many places in the Weald,
- Charcoal ('coals'), made in the many coppice woods in the Weald,
- A good stream of water, to power the bellows that created the 'blast'.
The blast furnace was a stone tower, roughly 5m square at the base and 6-7m high. Inside it was shaped like an upside-down bottle. Iron ore and charcoal were loaded through a hole at the top. At the tower's base were two arches: into one air was pumped by water-powered bellows; out of the other the molten iron was tapped into sand moulds.
Smelting took place over the winter, and a ton of iron would on average have been tapped every day. The furnace was kept 'in blast' throughout the winter campaign, and would have produced about 200 tons of cast iron a year.
Fernhurst Furnace was probably first built about 1590, one of the earliest in the western Weald. It was owned and run by a succession of different ironmasters during its two centuries of operation. It finally closed in 1776, the last in West Sussex - largely it seems because of competition from the coke-burning Carron Ironworks at Falkirk in Scotland.
The furnace was fully excavated and recorded in 1989-1993. Today it is looked after by the Fernhurst Furnace Preservation Group, which organises an annual Open Weekend each September, and which hopes to preserve the remains and make them more available to the public. They kindly helped with this note.
This fragment of a fireback dates from after 1760 - so one of the last products of the furnace.
An iron fireback increases the heat of a log fire by half. Early firebacks used everyday objects, such as rope or butter-moulds and fragments of furniture, as simple decoration. Later ones were often cast using carved wooden patterns, and displayed coats of arms, mythological and allegorical subjects, and scenes from nature. They could be very elaborate.
Lent by Robin and Carla Barnes of Fernhurst Furnace Preservation Group.
Hodgkinson, Jeremy. 2010. British Cast Iron Firebacks of the 16th to Mid 18th Centuries. Hodgersbooks.
Magilton, John. 2003. Fernhurst Furnace. Chichester District Archaeology 2. Chichester District Council.