Many Bretons, in the second half of the 19th century, are working in the quarries of slate of Trélazé, near Angers. Because of their language, these migrants must be flanked by a clergy coming from Brittany. These priests try to isolate their flock, for they want to protect them from bad influences in suburds which are lukewarm towards religion and rather progressive in the political sphere. This first contribution deals with difficult putting into place of these breton almoneries.Les Bretons sont nombreux, dans la seconde moitié du XIXe siècle, à venir travailler dans les carrières d'ardoise de Trélazé, aux portes d'Angers. Pour des raisons linguistiques, ces migrants doivent être encadrés par un clergé venu de Bretagne. Ces prêtres tenten...