Keeping the ever-hungry furnaces of Blaenafon burning wasn’t just a job. It was more like hard labour.

Twelve hours a day, seven days a week. In constant danger from fire or molten metal, poisonous fumes and heavy machinery. Never sure if a tumble in the price of iron would see you turfed out of your own home.

It wasn’t just the adults who suffered. Children as young as five were put to work. In 1842 Government inspectors discovered 185 children under the age of 13 working at the ironworks and its surrounding mines.

A quarter of them were girls – many breaking up iron ore by hand on the bleak hills above the yard. Writer AJ Munby noted approvingly that men would tackle the larger lumps: ‘Then the girls smash them up… lifting the hammer over their heads and bringing it down with manly skill and force’.

There are many other heartbreaking stories. Margaret Thomas, aged 15, splashed around barefoot pushing trams underground. Eight-year-old Lucretia Jones spent all day calling out instructions to the man at the waterwheel.

But furnace manager William Lloyd wasn’t exactly sympathetic. After all he’d been put to work in a Staffordshire ironworks himself at the age of eight.

‘The refinery boys work in some heat in the summer time and sometimes get burned, but not very bad,’ he said. ‘I worked a good deal harder than the boys do here.’