The basic product of early ironmaking was 'pig iron'.
Pig iron was brittle in quality due to impurities and the nature of its molecular structure and had to be converted into ' wrought iron ' by re-heating and beating with heavy hammers to impart the strength and tensile qualities required for more robust use.
An improved method of achieving this was ' puddling ' - the iron was heated in a reverberatory furnace which was normally top heated, the heat source not being in direct contact with the metal thus reducing contamination.
In charge of this furnace was the ' Puddler ',
a highly skilled and dangerous occupation which required physical strength, stamina and sustained concentration.
J.J.Davies, who was born in Tredegar but emigrated to America where he later became a prominent figure in Government, wrote an account of his early experiences as a puddler in his book - "The Iron Puddler", recently republished.
Extracts from "The Iron Puddler" by J.J.Davies
"So those early iron workers learned to puddle forge iron and make it into
wrought iron which is tough and leathery and can not be broken by
a blow. This process was handed down from father to son, and in
the course of time came to my father and so to me. None of us
ever went to school and learned the chemistry of it from books.
We learned the trick by doing it, standing with our faces in the
scorching heat while our hands puddled the metal in its glaring
After melting down the pig-iron as quickly as possible, which
took me thirty minutes, there was a pause in which I had time to
wipe the back of my hand on the dryest part of my clothing (if
any spot was still dry) and with my sweat cap wipe the sweat and
soot out of my eyes.
For the next seven minutes I "thickened the
heat up" by adding iron oxide to the bath. This was in the form
of roll scale.
The furnace continued in full blast till that was
melted. The liquid metal in the hearth is called slag. The iron
oxide is put in it to make it more basic for the chemical
reaction that is to take place.
Adding the roll scale had cooled
the charge, and it was thick like hoecake batter. I now
thoroughly mixed it with a rabble which is like a long iron hoe.
"ON THE BOIL"
For twenty-five minutes while the boil goes on I stir it
constantly with my long iron rabble. A cook stirring gravy to
keep it from scorching in the skillet is done in two minutes and
backs off blinking, sweating and choking, having finished the
hardest job of getting dinner. But my hardest job lasts not two
minutes but the better part of half an hour.
My spoon weighs
twenty-five pounds, my porridge is pasty iron, and the heat of my
kitchen is so great that if my body was not hardened to it, the
ordeal would drop me in my tracks.
Little spikes of pure iron like frost spars glow white-hot and
stick out of the churning slag.
These must be stirred under at
once; the long stream of flame from the grate plays over the
puddle, and the pure iron if lapped by these gases would be
oxidized and burned up.
Pasty masses of iron form at the bottom of
the puddle. There they would stick and
become chilled if they were not constantly
The whole charge must be mixed
and mixed as it steadily thickens so that it
will be uniform throughout.
I am like some
frantic baker in the inferno kneading a batch
of iron bread for the devil's breakfast."
"COMING TO NATURE"
The charge which I have been kneading in my furnace has now
"come to nature," the stringy sponge of pure iron is separating
from the slag.
The "balling" of this sponge into three loaves is
a task that occupies from ten to fifteen minutes. The particles
of iron glowing in this spongy mass are partly welded together;
they are sticky and stringy and as the cooling continues they are
rolled up into wads like popcorn balls.
The charge, which lost
part of its original weight by the draining off of slag, now
weighs five hundred fifty to six hundred pounds.
I am balling it
into three parts of equal weight. If the charge is six hundred
pounds, each of my balls must weigh exactly two hundred pounds.
I have always been proud of the "batting eye" that enables an
iron puddler to shape the balls to the exact weight required.
This is a mental act,--an act of judgment. The artist and the
sculptor must have this same sense of proportion. A man of low
intelligence could never learn to do it.
We are paid by weight,
and in my time, in the Sharon mill, the balls were required to be
two hundred pounds. Every pound above that went to the company
and was loss to the men.
The balls are rolled up into three resting places, one in the
fire-bridge corner, one in the flue-bridge corner, and one in the
jam, all ready for the puddler to draw them.
My batch of biscuits is now done and I must take them out at
once and rush them to the hungry mouth of the squeezing machine.
A bride making biscuits can jerk them out of the oven all in one
pan. But my oven is larger and hotter. I have to use long-handled
tongs, and each of my biscuits weighs twice as much as I weigh.
Suppose you were a cook with a fork six feet long, and had three
roasting sheep on the grid at once to be forked off as quickly as
possible. Could you do it?
Even with a helper wouldn't you
probably scorch the mutton or else burn yourself to death with
the hot grease?
That is where strength and skill must both come
One at a time the balls are drawn out on to a buggy and wheeled
swiftly to the squeezer. This machine squeezes out the slag which
flows down like the glowing lava running out of a volcano. The
motion of the squeezer is like the circular motion you use in
rolling a bread pill between the palms and squeezing the water
out of it.
I must get the three balls, or blooms, out of the
furnace and into the squeezer while the slag is still liquid so
that it can be squeezed out of the iron.
From cold pig-iron to finished blooms is a process that takes
from an hour and ten minutes, to an hour and forty minutes,
depending on the speed and skill of the puddler, and the kind of
I was a fast one, myself. But you expected that, from the
fact that I am telling the story.
The man that tells the story
always comes out a winner."