Progress Report, Seismological Laboratory California Institute of Technology, 1955

Abstract

Automatic‐calibration weight lifters for daily checking of amplitude response and phase have been attached to Benioff reluctance instruments at Pasadena, Tinemaha, and Isabella. Red safe lights of an improved type have been installed at most of the stations; these allow the use of a lighter and less expensive grade of recording paper. The vertical‐component recorder at Dalton has been transferred from film to the new paper.Three small house trailers are being outfitted as portable stations. Two portable seismographs using vertical and horizontal pendulums and variable discriminator transducers have been set up to record by the hot‐stylus method, and are maintained in reserve for emergencies. Several additional film‐recording units can be put into the field on short notice.