This stop is described only by Locher, who says:

Harmonic Flute, Flûte Harmonique is, briefly, an over-blowing Flute of the nature of our Flauto Traverso, very frequently arranged as a 4-ft. stop, in which case it is called Flûte Traversière Harmonique.

Audsley also mentions it in passing, citing the example in St.-Denis (see below), but provides no description.

Examples

Flute Traversiere Harmonique 8', Grand Orgue; St.-Denis, Paris, France; Cavaillé-Coll 1841.

Flute Traversiere Harmonique 8', Solo Expressif; St. Peter's, The Vatican, Rome, Italy; Cavaillé-Coll 1875 (a proposal that was never actually built).

Bibliography