10. Van Gogh must be referring to the earthquake in the Dauphiné on 18 February 1889, which registered 6-7 on a scale of 12 and was therefore a moderate tremor. The
Courrier des Alpes reported it on 21 February. We are indebted to Geneviève Patau, Institut du Physique du Globe de Paris, Département de Sismologie, for this information. A report of this earthquake in the local Arles newspapers has not been traced.