Affixes

A tachometer is an instrument which measures the working speed of an engine (especially in a road vehicle); a similar device which produces a printed record is a tachograph, used particularly of the device that measures the speed of a goods vehicle and the distance it has travelled. A tachistoscope (Greek takhistos, swiftest, plus skopein, look at) is an instrument used for exposing objects to the eye for a very brief measured period of time; tacheometry (also called tachymetry, see the next entry) is a method of surveying an area quickly using instruments designed for the purpose.