Imogen Lycett Green on ancient Sussex: The Wealden iron industry

If you grew up in Sussex, you’ll know the Weald once harboured a robust iron industry. The Ashdown Forest, you ask? Why, it’s where Henry VIII made his spears and swords for those pesky wars, you cry! The woods are full of hammer ponds. The rivers run orange, for god’s sake, the colour of rust. We are the iron people.

But do you really know how it’s done? I don’t. I twiddle a stainless steel fork between my finger and thumb and wonder how this fork here is connected to that iron underground, there in the Weald.

I don’t even know what iron is. Fe. That’s where we begin. Fe, short for ferrum, which is Latin for iron. We use the Latin root for our periodic table because it was the Romans who brought their expertise in metallurgy to Britain, specifically to the Weald, around the time of their invasion in 43AD. Iron is a chemical element, I discover. Iron is the most abundant element on Earth, forming much of the Earth’s inner and outer core. And when iron was displaced as a material for tools and weapons across Eurasia, smelting technology developed. Thus, in about 1200BC, the Bronze Age moved into the Iron Age.

Crucially, however, not much iron ore is to be found in central Italy, so as the Roman Empire expanded, and the Roman army demanded more metal for spears, shields and swords, axes and iron bars, it became part of the Roman imperial strategy to conquer places rich in iron. During the Iron Age in Britain (c600-100BC) we knew how to make weapons, of course we did, but it was Roman knowledge and manpower (and, crucially, need) which saw a rapid expansion of the iron industry here.

The Romans would dig pits in the clay beds roughly five yards across and twelve yards deep to extract the iron ore, which they lifted out with baskets on tripods. The 1st century Roman historian Pliny the Elder’s Historia Naturalis is our source for knowledge of the Roman iron industry. Already aware of the daylight robbery of the project, Pliny writes: ‘We trace out all the fibres of the earth, and live above the hollows we have made in her, marvelling that occasionally she gapes open or begins to tremble – as if forsooth it were not possible that this may be an expression of the indignation of our holy parent.’

In Book 34 of the Historia Naturalis, Pliny writes: ‘Iron serves as the best and the worst part of the apparatus of life, inasmuch as with it we plough the ground, plant trees, trim the trees that prop our vines… with it we build houses and quarry rocks… but we likewise use it for wars and slaughter and brigandage, and not only in hand-to hand encounters but as a winged missile, now projected from catapults, now hurled by the arm, and now actually equipped with feathery wings, which I deem the most criminal artifice of man’s genius, inasmuch as to enable death to reach human beings more quickly we have taught iron how to fly and have given wings to it. Let us therefore debit the blame not to Nature, but to man.’

Solemn reading. Extraordinary to be there at the inception of a technology and to recognise its potential for damage. In the hands of man. Two thousand years on, in the modern world, iron alloys, such as steel, stainless steel, cast iron and special steels, are now the most common industrial metals, due to their mechanical properties and low cost. Nuclear missiles and forks.

Smelting itself is the separation of a metal from its ore by heating and melting. The Romans built beehive-shaped clay ovens called bloomeries – so called because they produced a porous mass of iron and slag called a ‘bloom’ – to smelt the iron ore, and they fuelled the bloomeries in the Weald with charcoal. So you have a raw material and an oven. You have wood and, apart from manpower, you only need one more thing: water to cool the iron. Our undulating Weald was not only abundant in oak, silver birch and beech, holly as well as chestnut and hazel for burning, but in its deep, wooded valleys – known as ‘ghylls’ – there were flowing streams.

There still are. On the hunt for remnants of the iron industry in the Ashdown Forest, I set out on foot from Fairwarp to Furnace Wood. I had spotted two ponds on the Ordnance Survey map which, I thought, in a wood with such a name as ‘furnace’, may have been dammed to create waterwheels to power bellows and hammer iron into bars. The infamous hammer ponds. As it was, I only found two slow running streams, with tiny orange ponds. Then I got lost. But while I was lost, armed with the history I now knew, I was able to imagine the huff of the bellows, the crash of the hammer and sparks flying. The atmosphere was much enhanced by the autumn colour of the trees, and the iron-grey sky.

On its bed of sandstone and clay, the Weald stretches from Kent into Hampshire, across the whole of Sussex, and it’s in West Sussex you’ll find a more dramatic example of a hammer pond. Fernhurst Furnace Pond has a dam and a sluice, where you really get a sense of the power of the water. It’s funny to think of those twinkling woodland streams fuelling a war machine, but that’s what happened. As soon as a monarch went to war, the furnaces were stoked. Hammer ponds had their heyday in the 16th century, when England fought the French Wars for 30 years (1562 1598), then got involved in the Eighty Years War against the Dutch (1566-1648). In Ashburnham, near Battle, there is a complex of furnace, forges and boring mills, built by 1554 and also the last Wealden furnace to close in 1813.

The Wealden iron industry went into decline when coal and coke (not found much round here) began to be used to fuel iron furnaces instead of wood. Now the furnace pond at Ashburnham is dry, though in the stream still lie reddish ‘bears’ – rocks of imperfectly smelted ore and iron. It is the bears that turn the water, appropriately, burnt orange. From the local history of Ashburnham: ‘Young ironworker William Hobday often spoke of the end of the furnace’s last campaign, as reported in his obituary in the Sussex Express in 1883. Sadly, he revealed that a six-year-old boy also present drank a whole bottle of gin, and was dead before the doctor came. Rumour holds that inebriation allowed the furnace fire to go out prematurely on that particular day.’

Pliny says little about child labour in the metallurgy section of the Historia Naturalis, but, as an antidote to the destruction of humanity caused by the discovery of gold (money) and iron (war), he does offer medicinal advice: ‘Rust of iron is obtained by scraping it off old nails with an iron tool dipped in water. The effect of rust is to unite wounds and dry them and staunch them, and applied as a liniment it relieves fox-mange.’

It’s unlikely you’ll get mange in the Wealden woodland, but you will meet foxes as well as badgers, deer, birds and the occasional walker who is probably lost. The hammer is quiet, the forge all cold, the wheels lie still and the children are gone, but their ghosts remain.