Massey's Electric Log, S.S. Great Britain, Bristol, England (UK), 2012

Another extremely advanced technology on the S.S. Great Britain, like something out of Jules Verne (but long before he was writing), was this electric log. The turbine on the right was dragged in the water, turning a cable in a tube, and the instrumentation then serves as an odometer, maintaining accuracy over thousands of nautical miles. The instrumentation was supposedly not connected directly to the cable, but rather by electricity, making the engineering challenge arguably greater for the time.