Popular Mechanics August 1969 - Walking Beam Engine
A Simple Oscillating Engine
Alpha Stirling engine drawings - Home Model Engine Machinist
Bill's 1997 entry in the Sherline contest was this very intricate triple expansion steam engine. Not surprisingly, it took first place.
Cheap and Simple Steam Engine
Infographic: Electricity A visual cheat sheet about electrical physics, containing the most important formulas of current and Ohm’s law expressed through an impossible water circuit analogy. (by Pierluigi Scotolati)