A new viscometer suitable for measuring the viscosities of relatively fluid silicates, in limited ranges, has been devised. The method is based on the study of forced vertical oscillations of a solid platinum sphere in the melt. The viscometer has been used to measure the viscosity of Na2O.SiO2-K2O.SiO2 eutectic melt, over the temperature range, 1000°C to 1200°C. The results compare satisfactorily with those reported in the literature.