Folded letter from Bureau Central
This folded letter originated from the main Paris office (Bureau Central) on September 29, 1870, and was prepaid 20 centimes for the French internal letter rate to Castillones. Note that this letter shows the “Par ballon Monté” endorsement that was required on all balloon mail as of this date.
Theoretically, this letter should have been carried out of Paris aboard the Céleste, which ascended on September 30, 1870. Unfortunately, the Castillones datestamp on the reverse of this letter is too lightly struck to determine the arrival date, so it is impossible to identify the actual balloon with any certainty.
Paris/60 (collection) 29 September 1870
Castillones (arrival) ?