  Three three-component (bulge, disk, halo) model Galactic gravitational
potentials differing by the expression for the dark matter halo are considered.
The central (bulge) and disk components are described by the Miyamoto-Nagai
expressions. The Allen-Santill'an (I), Wilkinson-Evans (II), and
Navarro-Frenk-White (III) models are used to describe the halo. A set of
present-day observational data in the range of Galactocentric distances R from
0 to 200 kpc is used to refine the parameters of these models. The model
rotation curves have been fitted to the observed velocities by taking into
account the constraints on the local matter density \rho_\odotand the force
K_{z=1.1} acting perpendicularly to the Galactic plane. The Galactic mass
within a sphere of radius 50 kpc,
  M_G (R<=50 kpc)=(0.41+/-0.12)x10^12 M_\odot, is shown to satisfy all three
models. The differences between the models become increasingly significant with
increasing radius R. In model I, the Galactic mass within a sphere of radius
200 kpc turns out to be greatest among the models considered,
  M_G (R<=200 kpc)=(1.45+/-0.30)x10^12 M_\odot, and the smallest value has been
found in model II,
  M_G (R<=200 kpc)=(0.61+/-0.12)x10^{12} M_\odot.
  In our view, model III is the best one among those considered, because it
ensures the smallest residual between the data and the constructed model
rotation curve provided that the constraints on the local parameters hold with
a high accuracy. Here, the Galactic mass is
  M_G (R<=200 kpc)=(0.75+/-0.19)x10^12 M_\odot.
  A comparative analysis with the models by Irrgang et al. (2013), including
those using the integration of orbits for the two globular clusters NGC 104 and
NGC 1851 as an example, has been performed. The third model is shown to have
subjected to a significant improvement.
