Abstract: Apparatus for compacting soil or the like which is designed to be an attachment to a back hoe and to be powered by a hydraulic fluid motor. The drive motor is disposed on a vertical axis and rotates an element which has a generally planar surface oblique to its axis of rotation. This surface moves against a cylindrical drive member and causes it to wobble back and forth thereby providing a reciprocating action which is used to drive shafts on which are mounted tamping feet. The shafts are provided with contact surfaces at their upper ends against which the cylindrical drive member acts. The shafts are round and are closely fitted inside of round sleeves. These sleeves are greased to provide an effective dirt seal. There is a cam follower coupled with each of the round shafts and fitted inside of guide plates to assure a reciprocal action. A similar cam follower prevents rotation of the cylindrical drive member.