When light reached the cathode, electrons were emitted and traveled down the vacuum tube until they reached the anode. Lenard could then determine the amount of electrons reaching the anode by measuring the current through the wire using a set potential voltage (battery). Using this device, Lenard ran a series of experiments in which he varied the frequency and intensity of the light. Surprisingly, Lenard found that below a certain threshold frequency, no matter how intense the light was, there was no emission of electrons. Above the threshold frequency, the current (i.e. the # of electrons reaching the anode) was directly proportional to the light intensity.