Abstract
An outstanding geometrical problem of the last half of the nineteenth century was to discover a linkage mechanism for drawing a straight line. In 1864, a solution (Peaucellier Cell) was finally found by a French army officer Peaucellier (1832-1913). The Peaucellier Cell was based upon the fact that the inverse of a circle through the center of inversion is a straight line. The subject of linkages became quite fashionable among geometer, and many linkages were found for constructing special curves.This paper present the design of linkages under Cabri Geometry II, an interactive dynamic software of geometry. It is divided into six sections. The first section is to introduce definition and preliminary. The second section is about the general theorem of linkage and the drawing of straight lines, conics and other curves are discussed in the following three sections, respectively. The last section is another application of linkages.