Glass Message Board

mystery solved. i found someone on ebay selling a very similarly composed item with its label for Bertino Hand made in California. Clean with damp cloth - just as mine has.

well, christies sold a somewhat like minded glass vase by marcello fantoni. this is a commercial production and probably has nothing to do with him but the ideas are similar.

Thank you for coming back to us.  It's a really gorgeous piece   Great design and colour use.

You say 'most likely HP Sinclair'.  Is there an evidence source for that maker at all? 

m

the conclusion is that of my appraiser whom i assume used comparable pieces to draw a conclusion. the glass is unmarked.

  A footnote in a glass club bulletin from 2012 concerning dating of American canary glass contains this statement: "Bohemian glass scholar Olga Drahotova claims that "yellow and gold uranium glass was introduced both in the Reidel and Harrachs Glassworks in northern Bohemia, and in the Sumova mountains in southern Bohemia, almost simultaneously". BOHEMIAN GLASS,1400-1989, p. 69. The authors use of the term 'claims" in this instance seems to minimize Olga's statement. I was wondering what you think.

It is a strange word for the glass club bulletin to choose :

 Information here on Olga Drahotová (1932-2021) in the Journal of Glass Studies 2021:
https://www.proquest.com/openview/c9d29e91949b464e26fb0eac87e79913/1?pq-origsite=gscholar&cbl=49252


however, it's possible it wasn't used in a way meant to minimize Olga's statement in the book, but perhaps used because as far as I could see there were no reference sources given specifically for that comment by her, so nothing for them to reference to? Perhaps that's why they used the word.


- In the book  Bohemian Glass 1990 English Text, Copyright Flammarion, the chapter written by Olga Drahotová page 69 says what you've mentioned above.


- Interestingly a few years later in Farbenglas 1, Neuwirth W, 1993, gives more detailed information (if I've understood it correctly) about developments of uranium glass:
page 277
Under the chapter heading 'On the History of Uranium Glass'
'In the Uranium Compounds in Industry' (glassmaking and porcelain painting) of 1963,Franz Kirchheimer devoted an illuminating chapter pointing to a large number of early sources connected with the subject (Kirchheimer, 1963, p. 274ff.).  The ...'


Further on she says:
'...Some authors of specialised contemporary literature mention the use of uranium in glass-making on in passing or not at all. To draw the conclusion from this, that uranium was not used before 1840 to colour glass, would be incorrect.  It can be proved that the 'composition glass factories' of Bohemia knew about uranium's power to color glass - already before 1835 - at Blaschka, as can be gathered from surviving accounts ...'
She then lists in detail numerous surviving accounts which include uranium.

at the end of the paragraph it says:
'... If we assume - and there appears to be no evidence to the contrary - that these terms came about at the same time as the "raw compositions," we find the term "Annagrun" already before 1835; can it therefore still be connected with Anna Riedel?'

Neuwirth also says on page 277 'The history of uranium glass lies in obscurity'.

  I think making your cullet as a separate batch unusual and a extra expenditure of time and materials. Possibly " fugitive" ingredients would be fired out or at least stabilized. Probably unnecessary if you have enough of your formula on hand as cullet [glass rejects, etc.]. It was customary to buy outside cullet in this country as they were not in the business of making cullet. By and large this seemed to have worked well in general practice. A large batch using an oxide  somewhat difficult to attain you may not want to take the chance.

 

I'm probably misunderstanding or talking at cross purposes (because I don't have a grasp of chemistry for glass making so I probably shouldn't be discussing this at all to be honest ), but Pellatt mentions on page 78 (apologies I have realised the link I gave didn't go directly to this page in his book) within his discussion on how uranium glass is made, his regret that Klaproth doesn't give specific gravities in his analysis. Elsewhere in the book he mentions the uranium glass they made breaking and all having to be replaced.  So it just doesn't sound that easy to make.