Hands-On: A Historical, Technical, and Practical Look At Breguet’s Expérimentale 1 — Plus, How The Magnetic Escapement Actually Works



At the top and bottom, there are two wheels made of titanium, with the ramps (colored blue and red for “south” and “north” poles, respectively) made of samarium–cobalt connected to the titanium. The top wheel is oriented with the north magnetic pole facing outward, while the bottom is mirrored, with the south pole facing out. You can also see that the thickness of these wheels “ramps” up, literally, getting wider until there is suddenly a square breaking barrier stud. 

The two wheels are connected to the escape wheel’s pivot, with the gearing that would connect to the fourth wheel in a standard gear train. In between, there is now an additional third safety wheel similar to a conventional escape wheel in a Swiss lever escapement. Similarly, the pallets resemble a Swiss lever system. Instead of jewelled ends, there are two small samarium–cobalt magnets inset, with the wheels above and below having mirrored polarity. Two magnetic repulsive forces inherently have some magnetic potential energy. Here, the interaction between pallet magnets and magnetic wheels also ensures a constant force regardless of the mainspring’s power.

One thing to note about magnetic fields is that, although the ramp angle seems subtle, magnetic forces scale quadratically. By doubling the amount of material, you actually have four times the force. What appears to be incorrect in the diagram above is the polarity orientation of the pallets.