Nasard Gamba English?

This stop is listed only by Audsley, who says:

The name given by its introducer, George W. Till, of Philadelphia, Pa., to a labial dual stop, formed of a metal Gamba, 8 ft., having the compass of CC to c5, and a tin Nasard Gamba, 2-2/3 ft., of the same compass. The unison stop is voiced to yield a powerful string-tone, so as to firmly establish the unison pitch. The Nasard is voiced to yield a clear but a decidedly subordinate string-tone. The combined ranks, which speak on wind of 15 inches, produce a tone of wonderful richness and color-value; unlike anything known to be yielded by a single-ranked string-stop. The Nasard Gamba was designed for, and introduced for the first time in, the Swell of the Concert Organ in the Wanamaker Store, in Philadelphia, [Pennsylvania, USA].

Irwin mentions it in passing, without any definition. Other compound stops designed by George W. Till include Duophone, Nasard Flûte, Quint Flute, and Tierce Flute.

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