A stop of the Regal class, listed only by Audsley, who says:

The name given to a free-reed stop, invented by Érard, of Paris, and inserted by him in the Organ erected Tuileries, now destroyed. Like all properly-constructed free-reed stops, the Jeu Érard was furnished with very large boots. Its resonators were in the form of a short inverted cone, surmounted by a hemispherical capping, having a perforation, where the two forms joined, for the escape of the condensed air and the emission of the sound. The tone of this stop is stated to have been agreeable but rather muffled, as might be expected from a free-reed under such a resonator. The stop is now obsolete.

The illustration reproduced here is taken from Audsley's entry for Regal.

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