The earliest type of automatic crescendo device was the Rollschweller (German for "roll-sweller") or Walze (German for "roller"), seen in large Romantic music era organs of the nineteenth century, almost exclusively in Germany. It consists of a wheel and axle, which would be horizontally mounted directly above the pedalboard. When turned toward the organist, the wheel would activate a mechanism that would add stops to the registration.
The initial automatic crescendo device was the Rollschweller (German for "roll-sweller") or Walze (German for "roller"), commonly found in large Romantic music era organs of the nineteenth century, predominantly in Germany. It includes a wheel and axle mounted horizontally above the pedalboard. When turned toward the organist, this mechanism would add stops to the registration.