A catalog of Cepheid variables is used to probe the kinematics of the
Galactic disk. Radial velocities are measured for eight distant Cephei
ds toward l = 300 degrees; these new Cepheids provide a particularly g
ood constraint on the distance to the Galactic center, R-0. We model t
he disk with both an axisymmetric rotation curve and one with a weak e
lliptical component, and find evidence for an ellipticity of 0.043 +/-
0.016 near the Sun. Using these models, we derive R-0 = 7.66 +/- 0.32
kpc and v(circ) = 237 +/- 12 km s(-1). The distance to the Galactic c
enter agrees well with recent determinations from the distribution of
RR Lyrae variables and disfavors most models with large ellipticities
at the solar orbit.