Time dependence of the torque for different isothermal models with planets on fixed orbits. Top: circular planets for different values of the viscosity. The curves are ordered from high to small viscosity. For smaller viscosities the settling towards equilibrium takes longer. Bottom: evolution for our standard viscosity (ν = 10^-5) for different eccentricities. Due to the large time variability of the torque for eccentric orbits these curves use sliding time averaged values with a window width of 1 period.