CHAPTER XIV

BOILING DOWN THE PIGS


An iron puddler is a "pig boiler." The pig boiling must be done
at a certain temperature (the pig is iron) just as a farmer
butchering hogs must scald the carcasses at a certain
temperature. If the farmer's water is too hot it will set the
hair, that is, fix the bristles so they will never come out; if
the water is not hot enough it will fail to loosen the bristles.
So the farmer has to be an expert, and when the water in his
barrel is just hot enough, he souses the porker in it, holding it
in the hot bath the right length of time, then pulling it out and
scraping off the hair. Farmers learned this art by experience
long before the days of book farming.

And so the metal "pig boiler" ages ago learned by experience
how to make the proper "heat" to boil the impurities out of pig-
iron, or forge iron, and change it into that finer product,
wrought iron. Pig-iron contains silicon, sulphur and phosphorus,
and these impurities make it brittle so that a cast iron
teakettle will break at a blow, like a china cup. Armor of this
kind would have been no good for our iron-clad ancestors. When a
knight in iron clothes tried to whip a leather-clad peasant, the
peasant could have cracked him with a stone and his clothes would
have fallen off like plaster from the ceiling. So those early