 The dust was collected in a cotton bag within the machine.An example of this can be seen at the Walthamstow Pumphouse Museum

In 1898 Franz Burger of Fort Wayne, Ind.patented (#614,832 (Nov. 29, 1898) a "machine for cleaning fabrics", consisting of dual steam-powered "vacuum-chambers" (the first known use of the term "vacuum" for a cleaning device), a boxlike rectangular "extractor" with a perforated face and rollers to be pressed to the fabric, and a flexible connecting tube with a rigid tubular handle with a hand valve to turn off the suction 
when not needed; the whole unit could be mounted on a stationary base in a building or on a wheeled truck.