not perhaps the most exciting of pieces, but a real beauty of a quality tumbler when compared to the biscuit thick chunky jobs we drink from in a pub nowadays. standing at 6"/150mm - unmarked, but with a very sharply cut attractive star base, and blown very thin with a long lasting 'ding'. Appreciate it might be from anywhere, but was there some reason/purpose in producing tumblers with this sort of quality, and would anyone like to take a punt at age for me. It does have a fair amount of base wear, which makes me think it may well be at least 60 -70 old. Lastly, can anyone recommend a good book for C19 - C20 drinking glasses in general. Thanks for looking.