How did the twisting wire oppose the gravitational pull between the lead spheres?

In the Cavendish experiment, the gravitational attraction between the lead spheres was counteracted by the restoring force generated by a twist in the wire of a torsion balance.

The apparatus consisted of a wooden rod suspended from a thin wire, with a small lead sphere attached to each end. When larger lead spheres were placed near these smaller ones, the resulting gravitational pull drew the ends of the rod aside. As the rod rotated, it twisted the suspension wire. This twist created a restoring force—essentially a mechanical resistance—that opposed the gravitational attraction. By measuring the distance the rod moved and the time it took to oscillate, Cavendish was able to determine the gravitational force between the spheres, which ultimately allowed for the calculation of Earth's density.1