test-furnacen. a reverberatory refining furnace in which silver-bearing alloys are treated; also figurative.
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society > occupation and work > equipment > furnace or kiln > furnace > [noun] > furnaces for melting or refining metals > for treating silver-bearing alloys
test-furnace1877
1877 E. H. KnightPract. Dict. Mech.Test-furnace, one form of refining furnace for treating argentiferous alloy.
1896 Godey's Mag. Feb. 186/2 I don't believe that the immortal Sara Bernhardt could have gone through the fierce test-furnace of this rôle more superbly.