The illustration features two head shots of men wearing suits, ties, and hats.
The hat on the right appears to be a Derby or Bowler hat.
As for the hat in the left picture ??, perhaps a Porkpie hat?
This image will go well in themes like:
Vintage
Yesteryear
Masculine
Classic
Source:
Museum für Kunst und Gewerbe Hamburg
Steintorpl., 20099 Hamburg, Germany
MKG Collection Online
Sited as Public Domain / CC 1.0
CC 1.0 info can be found here
https://creativecommons.org/publicdomain/mark/1.0/