After being under construction for over two months a model of James Watt's first engine has just been completed. This is not an exact scale model of that first engine built in 1788, but rather a representation that displays some of the features, like the sun and planet cranking gears that were used to avoid patent infringement. The original prototype had many firsts. Like it was the first engine to use steam under pressure to move the piston. It was the first steam engine to produce rotary power. It was the first engine to be rated in "Horse Power". The first to have the speed controlled by a fly ball governor. It was actually the beginning of the industrial revolution. James watt and Matthew Boulton formed a partnership, and after building this first engine, built hundreds more that were used in the British Isles and Europe. This first engine, by the way powered polishing machinery in Mathew Boulton's factory for 70 years. That is a long time for something of that vintage. The engine is now preserved in the Science Museum in London. Look it up on the Internet, there is lots of history about it.
Shown below are a couple short videos, one showing a close up of that governor that actually controls the speed of the model, and the other more of a look around as it is running.