I love this wacky thing! I'm not surprised it has seen little use, as filled with tea would be a very difficult if not dangerous thing to use.
I don't know who William Barker was but he either had a good sense of humour or loved his tea.
A large piece and in great condition with little rubbing to the gilding.
There is no makers mark, but is probably Jackfield pottery.
This was Staffordshire earthenware of a red clay body with a lustrous black glaze which resembled Japanese lacquer. This was either oil-gilded, as in this case, or decorated with white
sprigged trailing vines. This type of ware is named after the Shropshire town of Jackfield, but was not made there.
Inscribed: William Barker, Wolverhampton, June 1905.