Abstract: An apparatus and method for cleaning surfaces and crevices of teeth wherein at least one tuft of filaments is rotated in a controlled reciprocating manner whereby the tuft is rotated a number of revolutionsin one direction and then rotated the same number of revolutions in the opposite direction. An alternative embodiment comprises a plurality of tufts of filaments, each of which is rotated in a controlled reciprocating fashion about its own central axis. Furthermore, immediately adjacent tufts are contrarotated. Each tuft is rotated about its own central axis, and placed in contact with the teeth whereby the filaments develop a twisting action dynamically and serially progressing from the base of each tuft to the opposite free ends of the filaments. The plurality of tufts are positioned in two parallel rows, each of which has adjacent tufts staggered with respect to each other.

Abstract: A collar of suitable material, such as rubber, plastic, wood, metal, or the like, placed in surrounding association with a locking handle of an automobile door, of the type which extend vertically upwardly from the inside of the window sill of the door and which has an enlargement or knob at its upper end, the collar serving to convert such handle, when it is in "locked-door" position, to one having a side wall configuration of substantially uniform diameter throughout its height, such collar having an inside diameter smaller than the diameter of the enlarged head or end knob of such handle, but sufficiently large to slidably accommodate the shank of such handle and having an upper annular surface shaped to conform to the underside of the enlarged head of such handle.

Abstract: A simplified but highly efficient fluid-amplified liquid spring shock absorber is provided by incorporating a plurality of DeLaval nozzles in the piston head or dashpot head of a shock absorber.

Abstract: A method of and means for demonstrating organic evolution, particularly as it involves the mechanism of natural selection. Background panels of multicolor and intricate design or pattern are used to provide simulated natural environments, and thin chips of different colors and shades -- and, in some instances, of different sizes and shapes -- are used to provide simulated animals or plants to be placed on the background panels. A population of a predetermined number of chips of a predetermined mixture of colors -- say, for instance, an equal number of from ten to twenty different colors -- is selected. The chips constituting the selected population are then spread in a single layer more or less uniformly on the surface of the background panel, and preferably in spaced relation, so that each chip is in plain view and is more or less detectible -- depending upon the color contrast existing between each chip, respectively, and the associated area of the background panel.