Seismogram of the earthquake in San Francisco on 18th April 1906 recorded by Giulio Grablovitz on the Isle of Ischia. The dramatic state of the document before the restoration are quite evident. The disinfestation, the cleaning and the lining with rice paper has allowed for the complete recovery of the scientific information contained in the recording. Over 600 seismograms of the geodynamic observatories of the isle of Ischia have been the subject of restoration work by SGA within the framework of the TROMOS project of INGV-SGA.