Not according to my definition of precise. Cavendish built his pendulum and placed it in a shed in his backyard. He then left it there for a year. During one year he made just 17 experiments. He calibrated the pendulum only once before he made his first measurement. During one year, the tension of the copper wire changed, the distances between weights changed. Cavendish ignored all these. What do you think. Are these signs of a precise experiment?