  We have developed techniques that allow simultaneous measurement of the
spatial size of the luminous colliding beam region and the angular spread of
beams in collision using e+e- --> mu+mu- events. These are demonstrated at the
CLEO interaction point of the Cornell Electron-Positron Storage Ring, CESR,
taking advantage of the small and well understood resolution of the CLEO
tracking system. These measurements are then used to extract the horizontal
beta, horizontal emittance and the vertical emittance and search for dynamic
effects at CESR.
