A Viola da Gamba of 16' pitch. Mentioned only by Bonavia-Hunt, who says:

Schulze's pedal violone and great contra viola da gamba at St. Peter's, Hindley, are very famous examples of wood string voicing, and speak on low wind pressures.
. . .
The Hindley contra viola (on the great) is a rectangular pipe, measuring at the 16ft. note 6 1/4in. by 5in., and this gives a mouth equivalent to the fourth mouth of a metal pipe: moreover, this is as it should be, as the 4ft. pipe and every pipe from this point upward is a metal one with a fourth mouth.
. . .
The scale of the 4ft. pipe is 2-3/16in. These metal pipes are cut up as high as four-elevenths of the width and blown to the fullest capacity on 2 7/8in. pressure (without beards or bridges), in order to match the tone and power of the wooden portion of the stop (CCC to BB). The power and pungency of the bass and tenor register are but little less pronounced than the pedal violone, which is voiced on 3 3/4in. pressure.

Presumably, the “contra viola da gamba” and “contra viola” he refers to are the same stop.

Compare with Gambenbass, and Contra Gamba; see also Contra Viola.

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