The Millikan oil-drop experim ent, w hich was the first experim ent to measure the charge of the electron, com pared the electrical force on a small charged oil drop with the force exerted on this drop by gravity. T he experim ent thus required a knowledge of the weight of the drop. This weight can be obtained by observing the drop falling with a constant term inal velocity w hen the gravitational force on the drop is balanced b y the frictional force due to the viscosity of the surrounding air. (The air is at atm ospheric pressure so that the mean free path of the air molecules is m uch smaller than the diam eter of the drop.) The term inal velocity with which the oil drop falls is inversely proportional to the viscosity of the air. If the tem perature of the air increases, does the term inal velocity of the drop increase, decrease, or rem ain the sam e?