Summary - TST 25

TRANSPORTES, SERVICIOS Y TELECOMUNICACIONES


Key Words: Optical telegraphy, forest wildfires, forestry Engineers, Valsaín (Segovia, Spain).

[ Abstract ]

The optical telegraphs arose at the end of the XVIIIth century as the first modern system to convey messages to distance, through ingenious codes. Introduced in Spain in 1799, optical telegraphs were displaced by the electric ones from 1855. However, they had application for years in local lines, in military operations and, what is less known, in forest wildfires prevention. With this last order, a system of optical telegraphy was installed in 1879 in the Valsain woodlands (Segovia, Spain), by the famed Forestry Engineers Roque Leon del Rivero, Rafael Breñosa and Joaquin Maria de Castellarnau. This telegraph won great fame in August 1879 to be the first to warn of an accident suffered by the Royal retinue in the Sierra de Guadarrama. Because of this success, it was ordered in 1881 the installation of other similar devices in several forest areas of Spain, and it is documented the installation of at least one, of very ephemeral life, in Zuera (Zaragoza). The paper describes the telegraph of Valsain and collects data about its operation, which is documented at least until 1888, as well as the news on the application of optical telegraphy in other Spanish woodlands.