To my mind doesn't have a typical first half C20 cut bowl look i.e. large geometric mitres with naturalistic forms, and instead has strawberry diamonds and a sort of hobnail cut with a band of slanting blazes towards the base. The base star has been cut accurately without misalignment (in the centre) and there are 32 points, which Wilkinson says dates to 1840 - 50. Has a long ring when flicked, and cutting feels sharp. Lots of wear to the outer edge of base. Height is about 4.25" - 110mm and diameter a little over 9" - 230mm. Very few bubbles, but does seem to have far more white stones than you'd expect on a C20 bowl - several quite large ones, and colour of glass is reasonably white. I've looked at the base of one or two other cut bowls, which appear quite flat or as from a mould, whereas this one shows a 'hammered' effect in the area between the star and edge of the base, which I've seen on my Georgian Anglo-Irish tumblers - signs of grinding the base flat, I believe.
It was a charity shop buy as much for interest of the cutting as the fact that it's virtually undamaged - but in view of the style of cutting and perhaps the star, just wondered if it might be something other than English - also is the 32 point star a reliable dating guide, or does that occur also on C20 bowls? - does anyone think it might be C19? - thanks for looking.