How to Measure CP Violation in Neutrino Oscillation Experiments?

We propose a new method for measuring CP violation in neutrino oscillation experiments. The idea is to isolate the term due to the CP-violating phase out of the oscillation probability by taking difference between yields of two (or three) detectors at path-lengths $L = 250 (\frac{E}{1.35 {GeV}}) (\frac{\Delta m^2}{10^{-2}{eV}^2})^{-1} {km}$ and at $L/3$ (and also at $2L/3$ in the case of three detectors). We use possible hierarchies in neutrino masses suggested by the astrophysical and the cosmological observations to motivate the idea and to examine how the method works.