A later, silver example, and this monster is just as big.

This one is 22" (57cm) in length and weighs 210oz 12dwt. Assayed at London in 1912, the main body is the work of J. Parkes & Co. and the inner liner manufactured by Hamilton & Inches of Edinburgh.
It came up for auction in 1977 as part of the 6th Earl of Rosebery's sale at Mentmore, Buckinghamshire.
Trev.