seismometrographn.
Etymology: < seismometer n. (combining form -metro-) + -graph comb. form.Previous versions of the OED give the stress as: ˈseismoˈmetrograph.
1894 9 Aug. 362/1 The new continuous-record seismometrograph of the Collegio Romano.
This entry has not yet been fully updated (first published 1911; most recently modified version published online June 2019).