The experimental determination of the response curves for forced vibration with velocity damping, using a moving-coil galvanometer, is described. The mechanism for producing a sinusoidal emf, of continuously variable frequency ranging from zero to 0.4 cy/sec, is described, together with a method for the determination of the phase angle between the driving force and the motion of the driven system. Experimental results, obtained with the apparatus, both for response curves and phase angle measurements, for various values of damping, are summarized in the paper.