Abstract: A viscosimeter having a first cell containing mercury or other electrically conductive fluid, a second cell containing a sample of fluid of unknown viscosity, and a pair of passages interconnecting the ends of the cells to form a closed circuit. A plurality of electrodes extend into the second cell in spaced relationship with each other along the cell's axis and are connected to an electrical circuit. Upon the opening of valves in the two passages, the conductive fluid urges the sample fluid through one of the passages and flows through the other passage into sequential contact with the electrodes in the second cell. The electrical circuit detects the rate of movement of the conductive fluid past the electrodes and produces an output signal related to the viscosity of the sample.