We present evidence for the occurrence of a white-light flare on 10 September 1886. It represents the third of such rare events reported in the history of astronomy. The flare was mentioned by Valderrama (1886, L'Astronomie 5, 388). In this article we have used the original logbook of the observer, J. Valderrama y Aguilar, an amateur astronomer that lived in Madrid and Santa Cruz de Tenerife at that time.