As such, the clandestine primary schools have not been much studied. On the
one hand, because the research on XIX th. century primary schools has focu
sed either on the action of the State of the action of the Church. On the o
ther hand, because the only use of the administrative sources and the globa
l reading of the statistics do not allow to take this phenomenon into accou
nt. As a matter of fact, when they have been pointed, the clandestine prima
ry school teachers are added to the regularly established teachers in the s
tatistics without being counted apart. The examination school by school in
Loire-Atlantique shows that, these schools, which are usually considered as
an obstacle to the professionalisation of the primary school teachers part
icipate by their quantity to the general development of the school. Moreove
r proof of their social usefulness, they often benefit on the support of th
e populations and local authorities and the tolerance of the county authori
ties. With the study of the clandestine primary schools, we are faced with
the sources used to write the story of the primary school and their interpr
etation.