  We determine the velocity distribution and space density of a volume complete
sample of A and F stars, using parallaxes and proper motions from the Hipparcos
satellite. We use these data to solve for the gravitational potential
vertically in the local Galactic disc, by comparing the Hipparcos measured
space density with predictions from various disc models. We derive an estimate
of the local dynamical mass density of 0.102 +/- 0.010 solar masses per cubic
parsec which may be compared to an estimate of 0.095 solar masses per cubic
parsec in visible disc matter. Our estimate is found to be in reasonable
agreement with other estimates by Creze et al. and Pham, also based on
Hipparcos data. We conclude that there is no compelling evidence for
significant amounts of dark matter in the disc.
