  In the current-driven, kink-type Tayler instability (TI) a sufficiently
strong azimuthal magnetic field becomes unstable against non-axisymmetric
perturbations. The TI has been discussed as a possible ingredient of the solar
dynamo mechanism and a source of the helical structures in cosmic jets. It is
also considered as a size limiting factor for liquid metal batteries. We report
on a liquid metal TI experiment using a cylindrical column of the eutectic
alloy GaInSn to which electrical currents of up to 8 kA are applied. We present
results of external magnetic field measurements that indicate the occurrence of
the TI in good agreement with numerical predictions. The interference of TI
with the competing large scale convection, resulting from Joule heating, is
also discussed.
