Masthead of the first issue of “Le Ballon Poste: Journal du siège de Paris” published 30 Oct., 1870.
During the Franco-Prussian War of 1870, Paris was under siege. The only way in or out of the city was by balloon; the French started making use of balloon mail. They used balloons to distrubute these newspapers detailing events within the besieged city. Brown University has scans.
Below, a cartoon of a Prussian soldier distracted by an escaping balloon.