1To Benjamin Franklin from ——— Guigon, 29 August 1778: résumé (Franklin Papers)
ALS : American Philosophical Society <Agde, August 29, 1778, in French: I am sending you a modest work on engineering and make bold to congratulate your country on its alliance with France, that generous protector of the weak. May America prove a faithful daughter!> He signs himself Maître de Chapelle de la Cathédrale d’Agde.