have to show my ignorance and admit to not seeing any 'blue' - I'm also unfamiliar with the expression 'charger' when speaking of drinking glasses, although I'm well aware of the expression 'let's charge our glasses.... and drink ..... etc.", when raising our glass to make a toast etc.
There is some terminology from the C17 - C18 where the word 'bumper' was used - as in 'a bumper of champagne' - and always possible that may have referred to some particular quantity of champers in a large glass. I'm aware of using the word charger when speaking of a large diameter glass/ceramic dish or plate.
The word crystal seems to get much over use - it may be perceived as simply the equivalent of the word 'clear' - so anything in clear glass is termed crystal. I suspect the word has its origins in the Italian word cristallo - something from the Venetian glass makers vocabulary when they knocked out soda glass a long way back, which without a decolourant came out with a dirty straw-like or smoky colour, but when they added manganese became clear, and reminded them, apparently, of rock crystal.
If a glass bowl rings very well when flicked, then it's probably lead glass - anything from 24% to 34% of oxide in the batch (labels showing 'full lead crystal') - lead glass also mostly shows as a slight bluish/greyish hue in the glass - but a pure long tone ring is mostly the giveaway. Some large bowls will ring simply because of their shape, but there is a difference in sound.
As a general rule, the more the glass has a yellow tinge then the less lead - or none - and the more of a greyish/blue tinge then a higher lead content. Lead glass also heavier than soda glass.
Glass containing some lead oxide content often referred to as flint glass - originally, as English flints used as the silica base, rather than sand or Venetian pebbles............. I could be wrong, but now unlikely that any glass maker uses flints.
Without boring the pants off everyone, just to say that Peter (oldglassman) has previously commented that the most reliable method to test for lead content is by use of uv light (blacklight) ....... soda glass fluorescing yellowish, sometimes vividly ......... lead glass will show as bluey grey, and more so the higher the oxide content.
Outside of rummers, I don't think the Brits. seem to have favoured square feet. They do occur on British rummers from c. 1790, quite possibly as a stabilizing feature on what were often quite substantial sized glasses, but they look to have suffered a demise about the same time as George III. In the U.K. they're found commonly on C18 and early C19 sweetmeats and related large pieces but as for drinking glasses it's likely that square feet were almost exclusively a feature of Continental drinking glasses.
Show us a picture please, if possible, of your square footed glass, and we'll see if possible to suggest an origin and date.
Whether one or both of these is hand made should be easy to determine, depending on such things as striations on the bowl, a pontil scar under the foot, and a general lack of perfect symmetry, and age too. Feet can often tell more about the nature of a drinking glass than almost any other part of the glass, and when showing drinking glasses here it's very helpful to show a picture of the underside of the foot.
Topic: Discussion: How to age glass (Read 1537 times)
