Abstract: An apparatus for moving a plurality of objects or containers for selecting, positioning, or retrieving one of the objects or containers organizes the objects or containers into two similar and parallel packets or stacks. The selection of an individual object is carried out by displacing each of the packets through a distance corresponding to the distance between adjacently stacked objects, and transferring the most upwardly or downwardly extreme object or container from one packet or stack to the other. The hoisting and lowering of the packets of objects is actuated by means of a plurality of screws engaging the edges of the objects, the displacement of an object or container from one packet or stack to the other is actuated by means of one of a pair of carriages moving transversely to the screws. The sequence of motion of the screws and carriages is controlled by two maltese cross-type gears.