The top video is of a four cylinder Stirling Cycle Hot Air Engine.

The actual engine exists and works when a heat source is applied to the ends of the cylinders to create a heat exchange flow between two pairs of displacement and compression pistons.

The crank mechanism is a unique swash plate design which not only looks spectacular but reduces friction by limiting the size and number of bearing surfaces. Engines of this type are not very powerful so friction is their main enemy. They are mainly made for ornamental purposes although working models have many practical applications.

The top bottom video is of the roofing protractor invention as seen on the ABC’s New Inventors television in 2008.

The inventor Derek Pater has produced his own instructional video showing how the device works. The tool has been licensed for production and distribution is several countries and is also available here.

   Stirling Cycle Engine Video

    Roofing Protractor Video