  A recent paper [R. Hollerbach and G. Rudiger, Phys. Rev. Lett. 95, 124501
(2005)] has shown that the threshold for the onset of the magnetorotational
instability (MRI) in a Taylor-Couette flow is dramatically reduced if both
axial and azimuthal magnetic fields are imposed. In agreement with this
prediction, we present results of a Taylor-Couette experiment with the liquid
metal alloy GaInSn, showing evidence for the existence of the MRI at Reynolds
numbers of order 1000 and Hartmann numbers of order 10.
