Choice of the parameters of a test stand for measuring the Cavendish constant

Reevaluation of an experiment performed by Heyl in determining the gravitational constant with the aid of a torsion pendulum placed in the gravitational field of two standard cylindrical masses. Using all the available information concerning the test stand used by Heyl, an estimate is made of the accuracy which he could have obtained in his experiment, and an attempt is made to determine the factors limiting the accuracy of his experiment. It is concluded that Heyl obtained a low accuracy in measuring the gravitational constant mainly because of the low accuracy of his measurement of the period of the pendulum oscillations. The factors responsible for the low accuracy of the latter measurement are enumerated, and an experimental scheme is described in which the effect of these factors is greatly reduced.