The sensitivity of a polymer melt spinline to local disturbances in the quench air flow was studied experimentally. Variations in the takeup diameter were found to be caused by perturbations in the local rate of heat transfer induced over a one-half decade frequency range of quench velocity fluctuations, but were insensitive to quench-induced mechanical fluctuations of the spinline. The major characteristics of the experimentally-observed frequency response are in agreement with a simple dynamic spinline model. INTRODLJCIION 'M. M. Denn arrived in Minneapolis as a new graduate student in the fall of 1961, hoping to do research with Rutherford Aris. Since Aris was teaching the graduate course in fluid mechanics, the obvious response to his question about the student's research interests was "fluid mechanics." "Ah," he said, "I don't really do that. You should talk to . ." Our student's research interests changed quickly, and he did manage to convince Aris to take him on, but he never accepted that the author of an outstanding text on fluid mechanics did not "do" fluid mechanics. This application of concepts of process dynamics to a problem dominated by fluid mechanics is therefore dedicated to Rutherford Aris on the occasion of his 60th birthday.