Trains loaded with pig iron, showing coke ovens on left and Monongahela River on right, Pittsburg, Pa., U.S.A.

Miner drilling and laborer loading "black diamonds" in the rough, Anthracite Mining, Scranton, Pa., U.S.A.

Carrying away and loading the pigs, blast furnace, Pittsburg, Pa., U.S.A.

Modern steel plant along the Monongahela River, Pittsburg, Pa., U.S.A.

Yards, showing moulds and travelling crane, steel works, Pittsburg, Pa., U.S.A.

Group of miners in the main tunnel (1 1/2 miles long) of a huge coal mine, Pittsburg, Pa., U.S.A.

Operators and their levers handling converters and ladles, steel works, Pittsburg, Pa., U.S.A.