Examines in detail the history of Maxwell's development of electromagnetic theory, and stresses that the textbook version of this discovery is usually inadequate or erroneous. (MLH)

Presents an effective way to demonstrate the difference between direct current and alternating current using red and green LEDs. Describes how to make a tool that shows how an AC voltage changes with time using the afterimage effect of the LEDs. (Author/NB)

Describes a procedure based on the assumption that during the rated lifetime of a light bulb roughly half of the radius of the filament evaporates. Explains how the filament's operating temperature can be deduced. (DDR)

Describes apparatus needed and instructions for conducting four experiments. Experiments focus on light waves, measurement of contact resistance, demonstration of longitudinal waves, and a simple method of measuring the refractive indices of transparent plates and liquids. (JM)