The Great Red Spot (GRS) on Jupiter is not located in a uniform flow but occupies a position at which the zonal wind varies strongly with latitude 1. The conditions in which Taylor columns form in these circumstances are critically dependent (J. W. Cottrell, unpublished; Woods Hole Oceanographic Institution G.F.D. Summer Programme. Student notes, 1971.) on the sign of the relative vorticity associated with the shear. On Jupiter the GRS is situated at a latitude where conditions are particularly favourable for the formation of a Taylor column, according to this model. Complementary to this theoretical approach we report here some preliminary results of the first experimental investigation into the effect of shear on the formation of a Taylor column. © 1975 Nature Publishing Group.