I think I'd like to own any piece of late C17 glass - whether it be a flask or something with Lynn rings - they all look very 'historic'
I have no knowledge of these older pieces since they are beyond my pocket, but nonetheless like to acquire some information as they concern a distinguished period of English glass making - and would like to pose some questions, which I'm sure Greg already has the answers to - and which will help me to understand a little more.
I'm aware, from the few books I have, that for perhaps 25 years after the death of Ravenscroft the lead oxide content was increased to a maximum of something like 33% (at which level it stayed for a long time). In view of Greg's comments regarding the flask...............quote............."my theory that the proper lead content with other ingredients helped with the stabilization of the glass in my example which makes me feel my flask was made shortly after the end of the Ravenscroft period." - suggests a similarly high lead content, and presumably if so then it must feel heavy for its size. Is that so? - and definitely not soda glass.
Despite the lead content, it probably won't ring, presumably because of its shape - so I guess no point in giving it a flick
- perhaps you have already had this tested for lead content Greg (although I believe it may not be possible to test for percentage content).
Had it not been explained which piece was which (in the first picture) I would, in my ignorance, have plumped for the right hand example being the earlier piece - I have become accustomed to being told that older, lead content glass, appears less bright and with a slightly leaden tone - partly because of the high lead content which was a characteristic from that period (and for probably the next 120 years) - I can see this colour in some of my own British Regency and Georgian glass.
The clarity of this flask is noticeable in comparison with the right hand piece, although I don't know what decolouriser might have been used at the suggested period of manufacture I believe that the use of manganese was known in the early C18, but what agent might have been used at earlier dates - or were they just very careful about avoiding the iron content and choosing very clean English flints.
As regards the wear on the sides of the foot and body, as we know, this doesn't in itself indicate any particular age - rather some rough use perhaps somewhere in the last 200 years, although leather would not be a culprit unless impregnated with something like quartz particles in some way.
Hope you won't think my questions too pertinent Greg, and feel sure you have the answers anyway