Naval engineer officer's cocked hat

Naval officer's black 'beaver' cocked hat lined with loosely pleated white twilled silk and a leather sweatband. The upper edged of the hat is edged with black silk grosgrain ribbon. A band of black silk lace woven in an oak leaf and acorn pattern is attached diagonally across each end of the right side of the hat only. The right side bears a black silk ribbon cockade and a single twist of bright gold bullion within a plain gold bullion loop for the rank of commander. The button to secure the twist and loop is missing. Each end of the hat bears an inset tassel consisting of five small gold bullions mounted above two rows of five purple bullion eyes, denoting an officer of the Engineering Branch.

Unknown. The absence of the button makes it impossible to tell whether this hat was originally worn by a member of the Royal Navy or Royal Australian Navy.