Thomas — I've just spent four hours drooling over your amazing collection! Grateful thanks for the English text. On viewing the source html to see who had designed and built your website (no luck there), I noticed an interesting and useful overview of the history of claret jugs, but I haven't found out how to access this from your home page.
I've only had three or four examples of Rock Crystal through my hands, all simple wineglasses, but I found them equally stunning. My main interest from a practical dealer viewpoint is in later engravers, like Mr Douglas of Walsh and Jack Lloyd of Tudor.
I was particularly intrigued by your David & Maurice Davis Birmingham 1901 claret jug, with engraving by Frederic F. Carder for Stevens & Williams. Recently I've been taking a close look at S&W's ribbed glass, and had dated it myself to approximately 1909–mid 1920s. Your example was engraved on a blank which was described by S&W as
Cut Notched and Split Rib, and was still being made in the 1920s. Their 1920s pattern 45666 jug was made in sizes from ½ pint up to 4 pints (about 2¼ litres). S&W's
Grotesque pattern is similar with four heavyweight ribs. It hadn't occurred to me before that blanks in these patterns provide irresistible neatly framed panels for the engraver. Your claret jug takes me back a further nine years, matching Mervyn Gulliver's cited date of c.1900 (p.218). Thanks.
And finally — have you considered how these ribbed blanks were made? I think that there is a strong likelihood that they were pressed, being transferred immediately while still hot to the master glassmaker for further work.
Bernard C.