Hi I don't know what a mini-mini seismograph is but it cannot be smaller than the Wood-Anderson torsional seismometer which has a horizontal pendulum all of 6 millimetres long. The instrument was sold in kit form by the Sprengnether Instrument Company of St Louis. It was designed to record a trace on a drum wrapped in photographic paper but one could substitute an electronic optical transducer for the drum. See "The Amateur Scientist" by CL Stong, Heinemann, 1962, page 229. This is the book which started me off on seismography. If you cannot access the book then I'll be happy to quote a few paragraphs for psn. Cheers all Danie Overbeek. __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>