Wiktionary
open-hearth
a. 1 Describing a reverberatory furnace used to make high-quality steel. 2 Designating the steel so produced.
Usage examples of "open-hearth".
As late as 1856 came the Bessemer process, and presently (1864) the open-hearth process, in which steel and every sort of iron could be melted, purified and cast in a manner and upon a scale hitherto unheard of.