Resistivity of Sr$_2$ RuO$_4$ under uniaxial stress

We report high precision resistivity measurements on single crystals of Sr$_2$RuO$_4$ under in-plane uniaxial stress. A specially built probe enables the stress to be varied continuously whilst the sample is at low temperature. The needle-like shape of the samples ensures that the strain is homogeneous in the region probed. We compare results for different directions of applied stress relative to the crystal axes.