the filling force of compacted tobacco in the fillers of filter cigarettes which issue from a filter tripping machine is measured for the purpose of increasing the quantity of tobacco in the filters when the filling force decreases and visce versa . the filling force can be measured by pneumatically deforming successive increments of the wrappers of discrete cigarettes and ascertaining the extent of deformation or by mechanically deforming an entire stack of cigarettes and ascertaining the reduction of the combined volume of cigarettes . the quantity of tobacco can be regulated by removing a larger or smaller quantity of tobacco from a continuous stream which is thereby converted into the filler of a cigarette rod or by changing the speed of a conveyor in the distributor of the cigarette making machine so that the conveyor withdraws a larger or smaller quantity of tobacco per unit of time . the measurement of the filling force is carried out with a delay following severing of the cigarette rod so as to enable the filling force to rise to a value which is at least close to the final value . in addition to regulation of the quantity of tobacco in the fillers of cigarettes in response to ascertainment of the filling force , such quantity is further regulated when it deviates from a preselected value . the necessary measurements are carried out by a beta ray detector which is adjacent the path of the cigarette rod .