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Uranium Glass (Page 4)

Several catalogues from Percival Vickers & Co. have also survived and these, together with design registrations, have enabled me to identify some of their products. As with Molineaux Webb, I think it is likely that the early Percival Vickers glass had a high lead content giving densities greater than 3g/cc, but between the mid 1860s and 1900 the density was about 2.80 g/cc with a range of 2.65 - 2.90 g/cc.

Two items I am confident come from this earlier period are a piano insulator and a tumbler (Plate 8). The former (Plate 8, right) is green, has a density of 3.00 g/cc and a uranium content of 0.22% by wt. It bears a diamond registry mark equating to registration 120613, 8th July 1859.

PLATE 8
Centre: pressed tumbler by Percival Vickers, Manchester, illustrated in an
1881 catalogue, but probably earlier in date because of its high density.
Right: piano foot registered by Percival
Yates and Vickers for Thomas Dawkins 1859. Left: piano foot in same
design but unmarked.

The deposition states: “Made and Registered by Percival, Yates, & Vickers for Thomas Dawkins, Little Warner Street, Clerkenwell, London”. From this it would seem that the original article was made by Percival Yates & Vickers but raises doubts as to who owned the moulds. The matter is significant, as I have examined several other examples of this design. These do not have the diamond registry mark on the underside but a pattern of either concentric rings or small squares (Plate 8, left). The density of these was 2.52 g/cc and they had a uranium content of 0.25%-0.28% by wt. I have also seen this pattern portrayed as made by the Crown Crystal Glass Company in Australia! There must surely be some doubt as to whether these un-marked piano insulators were made by Percival Yates & Vickers. If they were, then it was probably from resurrected moulds in the 1890s, which may then have been sold to the Australian firm. The tumbler is illustrated in an 1881 catalogue. It is in yellow and has a density of 3.16 g/cc. This, together with the quality of the moulding, leads me to consider it is older than the catalogue and probably dates from about 1860 or even earlier.

PLATE 9:
Left: opalescent swan posy holder by Burtles Tate, Manchester, design registry no. 20086 for 8th January 1885.
Right: lion paperweight by John Derbyshire, Salford, Manchester,
design registered July 3rd 1874.

A number of other items, which appear to be from Percival Vickers, have also been examined. Some are press moulded and some blown. They were probably made between the late 1860s and 1880s. Their densities are generally between 2.60 and 2.90 g/cc. and the colours green and yellow. The uranium contents vary considerably from 0.15% to 0.37% by wt. No doubt the other Lancashire glasshouses also used uranium, but I have little information on them. A Burtles Tate & Co. yellow opalescent swan (registry number 20086) has a density of 3.29 g/cc and uranium content of 0.25% by wt. A John Derbyshire green lion paperweight with diamond registry mark for July 3 rd 1874 has a density of 2.73 g/cc and uranium content of 0.26% by wt (Plate 9).

The Midland firms, better known for their blown lead glassware rather than press moulding, used uranium extensively. Here it was not only used in single coloured items but also in tinted and cased glassware. Thomas Webb & Sons is perhaps the best known and best documented. Eveson, in his Reflections, gives us a number of formulae utilising uranium that were used by this firm in the 19th century and three for the 1930s. The earliest uranium formula that Eveson has found comes from the 1880s, but it is likely that the element was used well before. Uranium is the colouring agent used in Webb’s Ivory, and, in several examples that I have

PLATE 10:
Group of Burmese glass, Thomas Webb & Sons, Stourbridge, late 1880s.

examined, the measured uranium content is consistent with the formula quoted by Eveson. Perhaps the best known of Webb’s products from the late 19th century is their “Burmese” ware (Plate 10) made under licence from Fredrick Shirley’s Mount Washington patent. According to published formulae it should be possible to differentiate between the Webb and Mount Washington products by their densities and uranium con-tents. I would expect the Webb’s product to be less dense, about 2.75 g/cc (compare 2.85 g/cc for Mount Washington), and to have less uranium. The formulae quotes “uranium oxide” but I consider it more likely that the uranium was a diuranate, as this would correlate better with my measured results. In this case Webb’s Burmese will have about 0.5% uranium by wt. compared with Mount Washington’s Burmese of 0.7%.

PLATE 11:
The standard colours from Thomas Webb’s Gay Glass range from the 1930s: Sunshine Amber (left), Bristol Green (centre), Eau de Nil (right).

In the 1930s Webb’s produced three standard colours using uranium: Sunshine Amber, Bristol Green, and Eau de Nil (Plate 11). These must have been made in considerable quantities, for examples are not difficult to come by at present day fairs. The uranium was in the form of potassium diuranate, and, neglecting the loss of water on fusion of the mix, the published formulae equate to uranium contents of 1.15%, 1.16% and 0.23% uranium by wt. respectively. I consider that the marked items of these colours are sufficiently reproducible for them to be used for Geiger calibration.

Stevens & Williams, now Royal Brierley Crystal, used uranium in both the 19th and 20th centuries. They may have begun using it as early as the late 1840s. I have examined several items from the 1880’s era where the uranium glass is cased with pink, where it is ivory and where it is even white (Plate 12). By the 1930’s they, like Webb, were using uranium in

PLATE 12:
Cased vase with applied acanthus leaf decoration, probably Stevens and Williams, Brierley Hill,
late 19th century. The
uranium is in the white opal outer casing. Unusually for this glasshouse the density is only 2.5 g/cc.

green and amber. I have not examined a sufficient number of greens to draw conclusions about the amount of uranium present, but their ambers are darker than Webb’s and have about twice the uranium content, i.e. about 2.80% by wt.

I have no idea when the Birmingham firm of John Walsh-Walsh first used uranium and have experienced considerable difficulty in identifying their early products.
The firm was established in 1851, so it could have been amongst the early users but I have no evidence of this. An advertisement in the Pottery Gazette and Glass Trade Review for November 1883 shows some of their wares in “Crushed Strawberry” and “Electric Blue”. On the basis of this I have attributed several items in the “crushed strawberry” (Plate 13) and possibly one in the “electric blue”. These items are made of at least two layers of metal and the uranium is not in the prominent strawberry or blue! They are examples of where expensive uranium glass has been used unnecessarily. The density of these items is about 3.2 g/cc or even greater. It is difficult to estimate the uranium content. It is not usually possible to present the full surface of the Geiger tube to the uranium layer; furthermore, this layer is probably not sufficiently thick to be of infinite depth. With these caveats I estimate the uranium content to be about 0.7% by wt.

PLATE 13:
Glass by John Walsh Walsh of Birmingham. Left: posy bowl in
crushed strawberry colour, 1880s,
density 3.2 g/cc; it is not clear
whether the uranium is only in the
inner casing or also in the pink.
Right: powder bowl in primrose
yellow, 1920s, density 3.2 g/cc.
The uranium is only in the outer
yellow casing.

On the basis of items illustrated in advertisements I have concluded that Walsh also used uranium in the 1920s and 30s. Their “Primrose” glass (Plate 13) is comprised of an inner layer of white and an outer layer of a bright primrose yellow. This contains uranium and, despite being a lead glass, responds moderately to UV light. Not all such uranium bearing items should be attributed to Walsh. I believe that Stevens & Williams also made this type of product. The densities are usually 3.2-3.3 g/cc; the uranium, again difficult to estimate because of the lack of infinite depth, is about 1.1% by wt. From examples which I have attributed as Walsh Pompeian glass, it appears that both the green and amber contain uranium, at concentrations of about 0.3% and 0.6 % by wt respectively. An iridised amber sweet dish, signed “Walsh England”, has a density of 3.28 g/cc and uranium level of 1.1% by wt.

No review of uranium glass could be complete without including the London glasshouse, Whitefriars, which was acquired by James Powell and Sons in

PLATE 14:
Uranium “topaz” finger bowl and ice plate from a set of twelve made for Queen Victoria’s banquet at the Guildhall in the City of London on 9th November 1837.
The glass and ceramics for this
occasion were supplied by the Staffordshire firm, Davenport’s, but it
is likely that the finger bowls were
made by James Powell and Sons.

1834. As far as I can establish, it was the first in the country to use uranium in commercial manufacture. The Whitefriars archives, held by the Museum of London, record that in 1836 some silver mounted candlesticks with prismatic drops of uranium Topaz glass made by Whitefriars were presented by Lord Howe to Queen Adelaide. The following year Whitefriars made twelve finger bowls and twenty-four hock glass bowls for use at the 1837 Corporation of London Banquet for Queen Victoria (Plate 14). I have had the opportunity to measure the uranium level in three of the bowls. The results are consistent with the formula in an early Whitefriars batch book. It is likely that Whitefriars used uranium to produce other colours and shades, but the only one I have identified is their pale straw opal items where I estimate the uranium content to be about 0.1% by wt.

Unfortunately density and uranium concentrations are not like finger-prints and cannot be the sole method of attribution, but they can provide supporting evidence where a specific regime has been established. A very good example of this is with Burmese. It is not unknown for the unscrupulous to grind off the “Fenton” signature and then try passing it off as Webb’s. A density measurement will soon establish the difference. Another example concerns the 1930’s reproduction “Georgian” glass. Examples can be found in Hill Ouston catalogue of 1934. The imitations are very good, even to the rough un-ground pontil mark, although in the case of wines the use of the foot-board to form the foot is a give away. I have examined several dark green goblets in this category and found them to contain uranium!

The foregoing represents only a brief synopsis of uranium coloured glass. Many examples can be found but most are un-attributable. To give some idea of the availability of uranium glass I would say that, on average, at the typical small antiques fair with, say, thirty tables, there are likely to be one or two pieces in uranium glass. Typical items include wine-glasses, bowls, vases, salts, piano insulators, paperweights, seals, knife rests, candlesticks, ashtrays, drawer knobs, lamp bases, lampshades, and even label moisteners. If an object has been made in glass, then the likelihood is that somewhere, sometime, someone will have made it in uranium glass. The problem is knowing what to collect.

Barrie Skelcher (1998).

Acknowledgements

I would like to thank all those who have supplied information and made documents available concerning the use of uranium in glass. In particular I would like to thank Mr Stan Eveson for information concerning the use of uranium at Thomas Webb & Sons.

All photographs are from the author’s collection with the exception of Plates 10 and 14, which have been supplied by courtesy of Broadfield House Glass Museum, Kingswinford.