A 10 m span, tensioned-wire strain seismometer is described which has successfully recorded solid-tidal strains in Britain. Secular drift is within a few parts in 10⁸ per week and sensitivity exceeds 1 part in 10¹⁰. Needing only two-point support it can be installed in a few hours for immediate use. The cost is comparable to that of conventional seismometers and is considerably less than current types of strain meters; it can therefore be used on an extensive scale for geophysics research.