This simple machine shows the workings of the Stirling
principle very well - it is built from glass parts.
Japanese site you find detailed instructions
how to build this machine and how it works. Again thanks
to Koichi Hirata!
The first picture shows all the parts that we have
On the rightmost picture you can see (well, almost)
how the marbles move the air between the hot and cold
areas of the test tube, thereby expanding and contracting,
which in turn moves the glass syringe on the left, which
again moves the test tube up and down.
Click on the Pics to enlarge.