While thumbing through an old issue of Modeltec magazine I ran across some line drawing sketches of early attempts to build electric-magnetic motors. One in particular, the Bourbouze, intrigued me and a quick search of the internet and I found that Google had an ebook with a picture of the engine, so I ordered a printed copy. Using a copier I enlarged the picture so it matched the size of a flywheel casting that I had on hand. Enough drawing was done to work out magnet dimensions, and other measurements were taken directly off the picture.
When Bourbouze built his motor about 150 years ago, he modified an existing steam engine with magnetic coils in place of pistons and a slide switch in place of a slide valve. Bourbouze's engine ran, but electricity at that time was usually provided by batteries because dynamos and generating equipment had not yet been perfected. Batteries of that time were expensive, and not very efficient. Consequently Bourbouze's motor was not competive with other power sources, such as steam engines.
I'm sure the picture that I followed to build my model is not of the original engine, but rather a model that someone before me had put together. Still I'm pleased with it. It runs fine on a 6 volt battery, and is completely different than anything I've built before. It is a good addition to the display room.