When subtracting two numbers, regrouping means starting at the ones column and borrowing a value from the next column as one moves to the left until the subtraction is completed. Regrouping and borrowing are words that mean the same thing when subtracting.
The Bessemer process was the first inexpensive industrial process for the mass-production of steel from molten pig iron prior to the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron.
But there was nothing to be compared with the solid steel article which the Bessemer process produced. Autobiography of Andrew Carnegie Andrew Carnegie Further purification is commonly carried on by a process very similar to the Bessemer process for steel. An Elementary Study of Chemistry William McPherson The Bessemer process was used much more extensively upon the Continent than in this country in the manufacture of castings.