  The Gravity Probe B (GP-B) satellite experiment will measure the precession
of on-board gyroscopes to extraordinary accuracy. Such precessions are
predicted by General Relativity (GR), and one component of this precession is
the `frame-dragging' or Lense-Thirring effect, which is caused by the rotation
of the earth. A new theory of gravity, which passes the same extant tests of
GR, predicts, however, a second and much larger `frame-dragging' precession.
The magnitude and signature of this larger effect is given for comparison with
the GP-B data.
