This is a good sized hat (fits my head !). These hats were referred to as fore and aft hats, cocked hats and also known as bicorn hats. This style of hat was widely adopted for military wear during the 18th and 19th century and on occasion these are still seen in use today. Also bicorn hats were used as part of court dress.
I sourced this particular example in Dublin. It is likley that it would have been worn at formal, full dress occasions in Victorian Dublin.
This silky styled hat is made from what I believe is beaver felt. The centre of the hat is fully trimmed with fine black coloured ostrich feathers. The central feature of the hat is a black watered silken cockade with vertical gilt bullion wire strips terminating with a fine, large gilt general service type Victorian crowned metal button.
Internally the hat has red lining in very good condition and the tan coloured leather sweat band is also very soft and not in any way dried.
There is some service wear on the edges of the hat.