At Saint-Louis, “hotwork” – when and whereby crystal glass is produced under high temperatures – is the essence of the great hall at the heart of the workshop. This is where the continuous-casting tank furnace is located, and where crystal fusion takes place at 1,350°C. Resembling an incandescent lava, rid of its impurities by fire and with time, the molten glass is deposited in the “gathering” areas. At these “gathering bays”, maintained at a constant temperature of 1,200°C, the glassblower gathers at the end of a rod the molten material needed to make a glass or decanter.
Then begins a kind of ballet with a repeated yet never repetitive choreography; a silent, coded narrative, where breath replaces speech, and the gestures, minimal, are mystical. The glassblowers are like ogres with the finesse of embroiderers. They are men with lung power, whose breath kisses and kindles the orange mass at the end of the blowpipe; then they place the molten glass in a mould of beech wood or steel, where, in a fury of flames and steam at 900°C, the initial form of the object, the parison, is pressed.
In a matter of seconds or minutes, working in small groups, the glassworkers perform a series of rapid sequences in which the eye, the hand and the mouth are the tools of the trade. There are also shears that cut, trim and open; wooden pallets that fashion and straighten; pincers that hold, stretch and twist; but the glassblower’s skill lies in his ability to blow and turn the rod at the same time while measuring the effects on the crystal, now at 600°C. This living, vibrant material has not yet finished with heat: placed in an annealing furnace, the objects gently solidify, passing from 450°C to an impeccable cold. Glasses cool in two to three hours, vases in three to four days, the time necessary to eliminate thermal stresses.