Each page has one machine, drawn in cut-away and moving, with the explanation stepping along beside it. Let it run, drag the dial to go at your own pace, or tap a step to jump straight to it. Nothing here takes more than three minutes.
None of these are stock illustrations. Each one is a working model, and the numbers in the text are worked out from that model in your browser as the page loads — there is a table at the bottom of every page showing the arithmetic. Change the drawing and those numbers change with it.
New ones get added as they get built. Engines, everyday machines and the physics underneath are where most of them sit today; offshore and subsea is where the next few are going — how a pipe gets laid on the seabed, how a crane keeps a load still while the vessel moves under it.
Start anywhere. None of them depends on another.