- Heat and cool gradually to soften - Heat and cool, to strengthen - Princess Royal and Pacino join forces to toughen metal - Temper metal etc - To subject to great heat, and then cool slowly, as
glass, cast iron, steel, or other metal, for the purpose of rendering
it less brittle; to temper; to toughen. - To heat, as glass, tiles, or earthenware, in order to
fix the colors laid on them.