Symmetry of compession waves about the octave node will always be perfect. In the hypothetical "sparkspin machine" the diamagnetic (and weakly electro-conductive) water strings are compresssed with a series of pulses by the action of the rotor. These constrictions will travel like peristaltic waves away from the octave node in both directions symmetrically. If the rotor is spinning then the combination of the four ball-ended spokes set against the stators' (7a) spacing will result in 4X3 (12) compressions per revolution. Symmetry of compession waves about the octave node will always be perfect.