The paper describes certain experiments designed to investigate the mode of penetration of tooth-ripple flux pulsations in smooth laminated pole-shoes. Simple measurements made by means of search coils embedded in holes drilled axially at different radial depths from the pole face have revealed that a dynamic mode of flux pulsation, which corresponds to the static tooth-flux distribution, persists, at significant amplitude, at the normal operating speed of the machine. Measurements have been made with two sets of laminations of different thickness and material at a range of tooth-ripple frequencies. The results provide substantial evidence in support of an analysis of tooth-ripple phenomena contained in a companion paper.