Watt's Parallel linkage

This construction shows James Watt's linkage for producing a straight line. You can manipulate the point B with the mouse. Notice that for small displacements of the point B, the point P moves in a very close approximation to a straight line.

Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and activated. (click here to install Java now)

C J Sangwin, 19 Jan 2006, Created with GeoGebra