Object use as character describer

Buster Keaton - Three Ages

Buster Keaton - Three Ages

A wrist sun clock and a helmet used as a lock. With this two examples, Buster Keaton describes a character that may not be wealthy, but is sure rich in ideas.

Portable clocks didn’t appear until the 16th century, but this roman citizen already had invented one.

As for the padlock, at that time they were already invented. Although most likely they weren’t used this way.