Double cone on inclined plane, C 1920

The mechanical paradox consists in a double cone which is able to climb up along an inclined plane. The double cone rises when the slope of the inclined plane is smaller than the product given by the tangent of half the cone’s angle and the tangent of half the angle of slide’s opening. So the phenomenon has nothing paradoxical, but it is in perfect accord with the laws of mechanics. Length Cone 32 cm and begin 20th century.