Consider a toy gyroscope, spun up to full speed and positioned horizontally with one end on the top of it's "Eiffel Tower" support, (see figure). Then you let go, and it starts to precess in a horizontal plane around the tower. Say it's actually a motorised gyro and the main gyro wheel maintains constant speed indefinitely. The speed of precession is a measure of the strength of the gravitational field which the gyro is within, and this arrangement could be used a gravity meter.

Consider then, an analogy between this gravity meter and an ammeter. If we remove the spring from a regular ammeter, then, of course, it becomes an electric motor. The needle rotates at a constant speed, proportional to the electric current, just as the gyro precesses at a constant speed proportional to the gravitational field strength.

The motor reaches it's equilibium speed due to back e.m.f. The analogy suggests an equivalent to back e.m.f. in the behaviour of the precessing gyro. What would this be? Once the gyro has started to precess, how does it know when to stop precessing any faster? To give a measure of gravitational field strength, the gyro must have drawn some energy from the gravitational field, presumably by dropping slightly as it's precession began. Is there an equilibrium exchange of energy, analogous to that in the electric motor?

My "wild" ammeter needle draws energy from the electrical supply as it accelerates, and then returns a significant amount of energy to it by back e.m.f. It operates simultaneously as a motor, and as a generator of electric current. Systems like this normally exhibit an equilibrium in energy exchange.

But if we apply this principle to the precessing gyro, the conclusion is rather surprising. It's "back e.m.f." would have to be back-gravitational field! This suggests that a precessing gyro creates a gravitational field. Are we sure that it doesn't?

The next part of this theory is an arbitrary assumption. That the important behaviour occurs at the start or end of precession, rather than during a period of constant speed of precession. After all, when we first let go of the gyro it stopped dropping, when it certainly would have dropped right on the table if it hadn't been spinning.

Say that, when precession begins, when there is angular acceleration of precession, the gyro really does create a pulse of gravitational field, which then becomes very small as the speed of precession reaches equilibrium. If this could be shown to be a real effect we could harness it by designing an apparatus which purposely gives a gyro angular acceleration in the plane of precession. Since this would be a gravitational field generator, we would have an "anti-gravity" gyro-lift device.

There is one major problem. We cannot make a device which accelerates forever to an infinite angular velocity of precession. What's needed is some sort of reciprocating device where the angular velocity of precession is increased and decreased cyclically. But then any useful force due to the gravitational field we have notionally created, would be upwards then downwards in alternate half cycles. We need somehow to "reverse the polarity" of alternate half cycles. We could try slowing the gyro down and spinning it up to full speed the other way on each half cycle. But this is hardly likely to be practical, especially in view of the fact that we almost certainly want the gyro to be heavy and spinning very fast.

The arrangement described below is a suggestion for getting around this problem. If there is a real link between angular acceleration of precession and gravitaional field, then this device, or something like it, should be an anti-gravity engine!