From the blast furnaces the pig, red-hot in its molds, is conveyed to the open-hearth furnaces, where it is subjected to a still further boiling process at the same temperature as before, and then it is steel. Steel is pig-iron combined with carbon and with the impurities boiled out.

It was to the blast furnaces that the Iron Boys were assigned, and they were to take the night trick. As they made their way that night through the yards of the mill, where engines were shrieking their warnings, cars were thundering here and there, long trains of red-hot metal rumbling over the hot metal bridge from the blast furnaces to the mills, while the flames were leaping skyward from the blast furnaces, Steve halted for a moment to gaze on the scene. Neither boy ever had been in the yards after dark, and the scene was one never to be forgotten.

"Which furnace do we work in?" wondered Bob.

"Number four, I believe."

"Then that must be the fourth one."

"Naturally it wouldn't be the fifth," answered Steve, with a laugh.

They hurried across the bridge, for it was already time they were reporting to the head melter at the furnace, and being late meant being docked, for there is no sentiment in the steel mills. Every man was expected to do his full duty and a little more. Most of them did the latter.

A scene of activity and apparent confusion met their gaze as they neared the towering blast furnaces with their heating stoves sixty feet high on either side of them.

Men with barrows were rushing about, bells clanged as the charge was ready to hoist on the top of the furnace to be dumped into its never-satisfied mouth. The ore was carried up by another skip. Through the stoves roared a gas flame, leaping, licking, here and there reaching out a forked tongue as though in search of fresh prey. The odor of gas was well-nigh overpowering to the Iron Boys, for they were not used to it.

The head melter, standing close up against the furnace, clad in a rubber coat and wearing green goggles, was peering into the furnace through a peep hole, while a stream of water from a hose was constantly played over his body. His face seemed to rest almost against the plates, and the bosh on which he was standing was so hot that the steam rose in a cloud about him.