Abstract: An upright duct in the distributor of a cigarette rod making machine receives identical quantities per weight of tobacco particles per unit of time. The volume of the column of tobacco particles in the duct is monitored by two photoelectric cells which transmit signals to a speed regulating device for the motor which drives a carded drum below the outlet of the duct so that the drum removes more tobacco when the volume of the tobacco column in the duct increases and vice versa. The particles which are removed from the drum are converted into a sliver which is thereupon converted into a narrow tobacco stream. The volume of the tobacco column in the duct fluctuates due to unforeseen changes in the size, moisture content and/or temperature of tobacco particles. The mechanism which delivers tobacco particles to the duct includes a weighing device which receives particles from a magazine and from a source of short tobacco.