The only way I could figure out that this cover flew Via Air France was the Paris postmark on the back. The flying business in 1936 was very, very small by today's standard; so much so that people mailed their air mail letters with a specific airline, and a not-so-small country like Argentina only had Condor, Air France flying their mail to Europe, and Pan American flying their mail to North America. There was also Aeropostal flying to South America... I think that's it for airlines!
