RECONSTRUCTION OF A BOSCH-OMORI SEISMOGRAPH

SUMMARY At the end of the XIX century, F. Omori started to design horizontal pendulums. The J. & A. Bosch brothers, from Strasbourg, commercialised a version of this instrument known as Bosch-Omori. Due to its simplicity and affordable price it was widely distributed. Nine such instruments were operated at seismic observatories in Spain. As a part of the interest of the Instituto Geografico Nacional (IGN) to recover its heritage and, also, to study in a direct way its recording characteristics, one of such Bosch-Omori seismographs has been reconstructed. This contribution presents the different stages of the reconstruction process and a study of some of the instrument features and characteristics.