Listed only by Irwin, who says: A mild String stop of 1-3/5' on the manuals, and 3-1/5' on the pedals, intended to furnish the fifth harmonic of the unison series in String tone. Its effect is sharp, even from a Diapason of this pitch, therefore it should be drawn with caution in those few organs in which this is an independent stop. It adds closeness of pitch to the complex of harmonics that would be heard from the whole combination in which this stop would occur. It is seen in the larger String Organs, where it is necessary for a complete complement of harmonics. It is less valuable than the String Twelfth or String Octave. It may sound from a String mixture. Soft Viola pipes may be used for it.
Viol Tierce 3-1/5', 1-3/5', Viol Organ; Cadet Chapel, United States Military Academy, West Point, New York, USA; Moller.