Adam P — your lovely tazza with a loop, with added acid-etched floral decoration, is illustrated in Hajdamach,
British Glass 1800–1914. Here the author attributes it to
Stourbridge, late 19th century. Note that throughout the book Walsh is included in this general classification.
Hajdamach describes it as
yellow opalescent, uncapitalised, although I would prefer the more contemporary "Canary Opalescent", a term that was unambiguous on both sides of the Atlantic.
Note that there are no features of your tazza that help narrow down this attribution at present. They all used 12-rib dip moulds (a pity it wasn't 18-rib), and the loop, once introduced, was widely copied. A detailed study of crimped leaf-like patterns might help, but I fear that the outcome could be the conclusion that they all bought their crimps from the same crimp salesman, whose lion's head prunt crimps seem to have been sold far and wide, from Gateshead to Murano. Nor does the glass itself help a great deal; they all made Canary Opalescent — the knowledge was probably spread quickly by mineral salesmen. Unless an example turns up in a readily identifiable glass, like Walsh
Mother-of-Pearl or Webb
Alexandrite, the best chance for attribution is the acid-etched floral pattern applied to the example illustrated in the book, but it is difficult to pick out any detail.
Bernard C.
