  We measure the Galactic rotation curve and its first two vertical derivatives
in the first and fourth quadrants of the Milky Way using the 21 cm VGPS and
SGPS. We find tangent velocities of the atomic gas as a function of galactic
longitude and latitude by fitting an analytic line profile to the edges of the
velocity profiles. The shape of the analytic profile depends only on the
tangent velocity and the velocity dispersion of the gas. We use two
complementary methods to analyze the tangent velocities: a global model to fit
typical parameter values and a local fitting routine to examine spatial
variations. We confirm the validity of our fitting routines by testing simple
models. Both the global and local fits are consistent with a vertical falloff
in the rotation curve of -22 +/- 6 km/s/kpc within 100 pc of the Galactic
midplane. The magnitude of the falloff is several times larger than what would
be expected from the change in the potential alone, indicating some other
physical process is important. The falloff we measure is consistent in
magnitude with that measured in the halo gas of other galaxies.
