"A muffle furnace, employed for annealing, hardening, and tempering." —Encyclopedia Britannica, 1910

Automatic Oil Muffle Furnace

"A muffle furnace, employed for annealing, hardening, and tempering." —Encyclopedia Britannica,…

"Automatic Oil Muffle Furnace." — The Encyclopedia Britannica, 1910

Furnace

"Automatic Oil Muffle Furnace." — The Encyclopedia Britannica, 1910