Two Wood-Anderson short-period seismograph,1933 Part - 1933 seismograph Object Number: 1974-539 Pt1 type: seismograph Image © The Board of Trustees of the Science Museum
Two Wood-Anderson short-period seismograph,1936 Part - 1936 seismograph Object Number: 1974-539 Pt2 type: seismograph Image © The Board of Trustees of the Science Museum