The viscosity of various viscous fluids was determined by the rotating cylinder method of measurement in which the radii, R1, R2, of outer and inner cylinders, respectively, the distance, δ, between the bottoms of inner and outer cylinders, the dipped length, l, of the inner cylinder in the fluid, and the speed, t, of rotation of the inner cylinder were changed to some extent, and the following conclusions were derived from the results of the measurements:
(1) For the examination for Newtonian by this method, the selection of the dimensions for l, δ, R1 and R2 may be arbitrary.
(2) The value of the end correction, f, is the function of l and δ.
(3) When R2 is kept constant and R1 is small, the value of f increases as R1 decreases.
(4) For the viscosity measurement by the rotating cylinder method, accurate measurement of l is necessary.
(5) The methods of measurement of viscosity used by H. R. Lillie and F. W. Peston is ressonable from the authors' point of view.