Rollschweller (Ger.: ‘roller swell’)
(Ger.: ‘roller swell’)
In German organs of the late Romantic period the equivalent of the crescendo pedal, used to engage or disengage a series of stops; it is sometimes also called Walze. It is operated by rotating a large roller with the foot, and there is sometimes a second roller (Pedalmoderator) controlling only the Pedal stops. ...