(Fr. abrégé; Ger. Wellenbrett; It. catenacciatura, riduzione). In an organ with tracker action, the part of the action that transfers motion sideways, usually from the trackers attached to the keys to the trackers attached to the pallets in the Soundboard (see Soundboard (i) and Organ, §II, 5). Its invention was essential to the development of the keyboard in its present form. The term in English dates at least from 1632. Talbot (c1695, MS, GB-Och Music 1187) described the ‘Rowlers’ and ‘Rowler-board’ mechanism thus:
between the Keys & the Palats belonging to them are several round pieces of Wood wch are call’d rowlers because they are made to rowl or turn in a centre upon little pins of Wire th[a]t are pass’d from each end of every Rowler into a small square bitt of wood that is fasten’d to the Rowler-board by wch the Rowlers are supported each Key having its distinct Rowler, between which & the Key there passes a slender Rib of Deal wch at the bottom end is fasten’d to the Key & at the top, to a Screw or Pin of Iron th[a]t is fix’t in the inside of the Rowler towards one end: on the same side of the Rowler towards its other end there is another Screw or Pin (answerable to the former), from wch there passes up another Rib to the Bottom of the Wind-box.
MARTIN RENSHAW