This thesis is concerned with the measurement of electron drift velocity in the positive column of an unmagnetized, low pressure, arc discharge using a microwave dragging technique based on Fizeau's famous experiment. The discharge is analyzed as if it were a cold plasma drifting with a velocity equal to the average electron drift velocity through the discharge; and to this end, an expression is developed which relates the index of refraction in the observer's coordinate system to that in the rest system of the plasma.

The experimental arrangement used to attempt these measurements is described, but the actual measurements were unsuccessful. Calculations were performed assuming a magnetized plasma, and encouraging results were obtained.

Electron density measurements made on the positive column of the discharge yielded values of 1.5 x 10^12 to 2.0 x 10^12 electrons per cm^3.