Comment on "Modulated-source Eötvös experiment at Little Goose Lock"

A Cu-Pb torsion balance placed next to a large lock on the Snake River permitted setting limits on the coupling constant for a possible intermediate-range material-dependent gravitational force. A 1,7&10kg perturbing mass of water could be turned on or oft within 12 min and had a well-known distribution. No evidence for a fifth force was observed. The experiment is primarily sensitive to isospin coupling, for which it yields limits on the intrinsic coupling coefficient ranging from ao=( —2.2~4.6)&&10 ' at k =10 m to ao=( —0.5+ 1.0) & 10 ' for X ~ 200 m.