The resonant air column consists of a 1-meter long lucite cylinder filled with water. A second smaller diameter 1ucite cylinder fits inside of it. There are two resonant columns, one with a diameter of 6 centimeters and the other a diameter of 3 centimeters. Sound is produced by a small transistor-radio speaker that is mounted on a wire gauze and can be placed above the columns. The speakers are driven by a General Radio audio-oscillator. The first quarter wave resonance length is greatly influenced by edge effects which are different for the two size columns. However, (provided the frequency is not too low) one can obtain many resonances whose lengths are separated by half wavelengths. If the inner tube is removed completly from the water column, one can establish the resonant conditions for an open ended tube. The columns can also be used to explore the harmonic distortion of these very poor quality speakers.