  We report test results searching for an effect of electrostatic charge on
weight. For conducting test objects of mass of order 1 kilogram, we found no
effect on weight, for potentials ranging from 10 V to 200 kV, corresponding to
charge states ranging from $10^{-9}$ to over $10^{-5}$ coulombs, and for both
polarities, to within a measurement precision of 2 grams. While such a result
may not be unexpected, this is the first unipolar, high-voltage, meter-scale,
static test for electro-gravitic effects reported in the literature. Our
investigation was motivated by the search for possible coupling to a long-range
scalar field that could surround the planet, yet go otherwise undetected. The
large buoyancy force predicted within the classical Kaluza theory involving a
long-range scalar field is falsified by our results, and this appears to be the
first such experimental test of the classical Kaluza theory in the weak field
regime where it was otherwise thought identical with known physics. A
parameterization is suggested to organize the variety of electro-gravitic
experiment designs.
