Annealing

(an-ēl´ing), a proce to which many articles of metal and gla are subjected after making, in order to render them more tenacious and which consists in heating them and allowing them to cool slowly. When the metals are worked by the hammer, or rolled into plates, or drawn into wire, they acquire a certain amount of brittlene , which destroys their usefulne , and has to be remedied by annealing. The tempering of steel is one kind of annealing. Annealing is particularly employed in gla -houses, and consists in putting the gla ve els, as soon as they are formed and while they are yet hot, into a furnace or oven, in which they are suffered to cool gradually. The toughne is greatly increased by cooling the articles in oil.