Organ pipe

From Ccpi

Organ pipes came in a variety of forms, each with specific additions for making certain adjustments or performing certain tests. Besides the traditional pipes that may have been made of wood, zinc, tin, etc, there were: double pipes, in which one mouthpiece supplied air for two pipes; pipes that produced a range of tones by way of an adjustable, graduated piston; pipes with adjustable membranes, for demonstrating different vibratory nodes; pipes with adjustable holes at the nodes; pipes for demonstrating that the position of the mouthpiece does not affect the tone; and yet other pipes demonstrating the influence on tone of the volume of air and the shape of the pipe.

An interesting piece in the collection of the Case Physics Dept., purchased from Max Kohl, Chemnitz, is called Kundt's covered pipe. On the opposite end from the mouthpiece, three tubes run down to the front of the pipe, on which sits a set of glass tubes, each with connected at the bottom to a brass valve. The glass tubes would be filled with water, with the valves initially closed. Upon supplying air to the pipe through the mouthpiece, the valves are opened, and the air forces out the water from each glass tube. Because the triple pipe was designed to produce three different tones, the water from each tube is pushed out at a different pressure, resulting in a different trajectory for each stream of water.