This work also requires frequent annealing, for otherwise the wires or tubes would rupture.
The second system is especially used for annealing large and heavy objects.
This was passed again and again between gradually approximated rollers, with occasional annealing, until the desired thickness had been attained.
To secure the highest possible permeability it is essential that the iron should be softened by careful annealing.
The bowl is severed from the blowing iron, and the wine-glass is sent to the annealing oven with a bowl, longer than that of the finished glass, and with a rough fractured edge.