This is a faithful photographic reproduction of a two-dimensional, public domain work of art. The work of art itself is in the public domain for the following reason:
This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 100 years or less.
The source is the Biblioteca Nacional de Portugal.
https://commons.wikimedia.org/wiki/File:O_duello_Floquet-Boulanger_-_Diario_Illustrado_(2Ago1888).png