Part 8, Air Twist Stems. 1730 - 1780.
Part 8, Air Twist Stems. 1730 - 1780.
The inclusion of air in the stem as a decorative feature has a long history. However, it fell to the English glassblowers to exploit the idea a simple tear or air beads to form a complex pattern within the whole length of the stem. Unlike Venetian soda glass or Bohemian chalk-potash glass the natural refractive properties of lead crystal enhanced this treatment particularly by candle-light when held high for a toast. Many of these glasses are engraved with sentiments suggestive of toasting, particularly the Jacobite cause.
Although I have not seen it mentioned before it does seem that the English glassblowers were less constrained in their creativity than their continental counterparts. One gets the impression that, for ordinary tableware, mass production was more important for the overseas glassmakers than the quality or diversity of the product. The English glass was never considered cheap by comparison and is hardly ever of poor quality.
We have already met the air twist used as an occasional feature in Newcastle glasses (Part 7). The symmetrical arrangement of a series of air threads forming a helix up the stem (called a multi-spiral air twist; abbreviated "MSAT") seems to be the earliest arrangement. It was obtained by piercing the gob of hot glass, first attached to the bowl, with a circle of nails fixed in a suitable wooden former. The stem was then drawn and simultaneously twisted to form the spiral. It was easily achieved by rolling the blowing iron along the arms of the glassblower's chair while using the pucellas to stop the end of the stem from rotating. Glassblowers are always taught to work right-handed and this is why all English twists rotate in the same direction. The MSAT remained a favourite throughout the life of the air twist, particularly in conjunction with the drawn trumpet
The air pattern could be varied by altering the arrangement of nails in the former. The simplest form of twist, produced by a single nail slightly off centre, is a single air bubble in the form of a slight helix down the middle of the stem. If a flat oval rather than a round nail was used refractive gave a shining surface to the thread so bright that it was suggested that the threads had been filled with mercury! This impossible proposal has long since been disproved but the name mercury twist has stuck for this decorative variant. Replacing the single nail by a tight cluster of thin nails has a similar result but now looking like a rope or cable. Two opposing sets of such nails give a double cable and so on. Because many of the twists were separate components of 3-piece glasses the original form of the stem could be made much thicker and then drawn out in the manner of seaside rock to give the final fine stem. Although the method appears crude the outcome lay in the skill of the glassmaker, the tightness of the twist affecting its appearance for example. Knopping is common in the MSAT glasses and the twist generally runs through the knop rather than the knop being added as a separate feature.
As with plain stems a wide variety of bowl shapes were used, particularly a tall round funnel. This is often engraved with an hops and barley motif and is consequently termed an ale glass (should be "beer" as ale did not have hops!) although probably used for wine as well. Mould-blown decoration to the lower part of the bowl - ribbing or a hammered or honeycomb effect - enhances the appearance and desirability of some examples.
Generally speaking, air twist glasses tend to have plain feet. A folded or domed foot is an additional feature to look for in this delightful and typically English series.
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