A large, brass Kit Bag Lock.
This example is a little chunkier than most and feels stronger for it. Kit Bag Locks were used to secure your possessions whilst travelling, be it to a rail on the train or simply as an extra lock joining the pair of handles of your bag. It would have been useful to any traveller wishing to guard against theft.
It has a later, associated padlock with it by Triangle which is interesting in itself as the whole steel bar is removable. Circa 1900.