tampon d'oblitération

CONT: Un bureau de poste livrait des timbres spéciaux et le tampon d'oblitération reproduisant l'insigne du congrès : une abeille tenant le monde en équilibre entre ses antennes.

CONT: Post office cancellation stamps are made of metal and contain a movable date section, which is changed each day. They use rather crude ink based on carbon black in a glycol-based substrate. It is necessary on occasions to establish where a letter was posted by comparing its postmark with a large number of impressions from all of the cancellation stamps in a large city.