Linkage mechanisms were first used in a number of applications dating all the way back to the 1500s. Machine theory was the work of Archimedes and Hero of Alexandra. Leonardo da Vinci then brought the concept to machinery and mechanisms. In the 1700s James Watt discovered that the steam engine's efficiency could be improved by adjusting the cylinder strokes for the expansion and condensation of steam. He then went on to develop the crank and slider mechanism into something that he could use in the steam engine. It was not until the late 1800s that F Reuleaux, A B W Kennedy and L Burmester developed a system to identify linkage systems by using geometry. It is down to these studies and developments over the years that linkage mechanisms are such a useful mechanical component and serve so many purposes today.