the revolution and rotation thus occurs in combination when material is present the rotation of agitator 50 causes the projections or fins 52 to bite into and loosen the material within the hopper along virtually the entire height of the hopper below the rotor arm as material is loosened it drops freely via gravity to the outlet end 28 where its outflow is further controlled by the sliding plates 46 47 which may be adjusted as desired if more positive feeding is desired rotation of the motor 40 and thus ultimately agitator 50 can be selected to rotate agitator 50 or 50 39 counterclockwise in fig3 such that the fins 52 force the materials downwardly alternately the motor may be operated in the reverse direction to rotate agitator 50 or 50 39 clockwise in fig3 causing a lifting of the material in the hopper allowing it to drop by gravity into the outlet end and avoid undue pressure on the sliding gate or plate 46 at the same time the agitator 50 is biting into the material such action resists rotation of the agitator and thus shaft 78 such resistance to rotation is transferred via shaft 78 to chain 88 so that revolution of rotor arm 62 about axis 60 is further induced it will be.