... Sowerby might be a stretch, though, as catalogs have survived from them. ...
Not my view. Sowerby should be easily at the top of your list of possibilities, by a long way. Consider the following, sourced from Simon Cottle's book on the glassworks.[list=1][*]Sowerby's glass recipe book dating from 1802 (that's 1802, not a misprint) to 1835 has survived, detailing daily experiments into the manufacture of a wide variety of flint and coloured glasses.
[*]The earliest surviving trade catalogue is No. IX, dating from 1882. There were eight previous catalogues of which we know nothing.
[*]Sowerby pattern numbers were sequential, presumably starting from 1, right through to when they closed. And they used just one number for all products made to one design. The earliest precisely dateable pattern number is 1135, registered March 6 1876. So there are 1134 earlier patterns of which we know almost nothing.
[*]Sowerby did not start using the peacock's head trademark until 1876, so none of those 1134 patterns would have been marked in any way.
[*]By the mid-1860s Sowerby was by far the largest pressed glass works in England, and probably in the world, with eight ten-pot furnaces, and over 450 employees. They were producing over 30 tons of finished glass every week. That's 3,500,000 lbs of glass every year.[/list:o]I think it is fair to say that any collection of unmarked Victorian pressed glass, anywhere in the world, will contain a high proportion of Sowerby glass.
The problem is identifying it. One day, perhaps, as is already happening in the paperweight field, calibration of the glass itself, in respect of its density, colour, fluorescence, and radioactivity, will start to yield results.
Bernard C.
