Gyroscopic precession is the reaction that a spinning object has to its axis of rotation being tilted.
Unbeknownst to the first observers, this “invisible hand” is actually the effect of what is called gyroscopic precession. Spinning up the disc in the frame, followed by holding the frame at different angles, resulted in a fascinating phenomenon where the rotating disc resisted its repositioning. To do this, each end of the spinning top axle is connected to the frame using bearings or some other means to minimise friction between the axle and frame. The method developed to enable more careful observation was to capture the spinning disc within a mechanical frame so it could be manipulated without touching the disc. The faster the disc spins or the larger its moment of inertia, the greater its angular momentum will be. Increasing the mass of the disc, especially when the majority of its weight is toward the outside of the disc, and increasing the spin rate, extended the duration of the spin induced balance. Using a flat disc with a pin through the centre of it as the spinning top made the balancing phenomenon more observable.