Computer animation by Java-Applets can help to study principles and behaviour of machines from the past. In former times the knowledge of "how to do something" was not written down because it was traditionally given from the older to the younger (e.g. craftsmen, machinists). As the simulation of processes in nuclear plants or airplanes is absolutely necessary before starting them, these tools can also help industrial archaeologists to understand for example working of waterwheels or steam-engines. Since 1995 there had been excavated two waterwheels in the mining region of the Harz-Mountains, which were used more than hundred years before as winding machines to bring up rocks and ore from the earth and put down materials and machines.
What are the elements of the construction and which are the important parameters for driving the machine? Using a computer applet for this example we can show the principles of working, restriction by physical laws and tricks to reduce water consumption.

waterwheel : www.pe.tu-clausthal.de/AGBalck/kehrrad/kehr-d.htm
steam-engine: www.ifg.tu-clausthal.de/java/damp/damp-d.html

Keywords: waterwheel, applet, animation