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Keywords from Image Description:
Brevet boule de Moulins schema. en Schema of PierreCharles Delort for the patent of submarine sphere then called boule de Moulins'and used to transport mail during the siege of Paris of fr Texte de PierreCharles Delort pour le brevet une sphre sousmarine appele ensuite boule de Moulins et qui utilise pour le transport du courrier