Steady shear flow Stressmeter data for N 1 — N 2 and shear stress σ near 20 ° C for increasing and decreasing values of shear rate γ . in the range 14–427 s −1 exhibit hysteresis and evidence of polymer degradation; N 1 and N 2 denote the first and second normal stress differences in steady shear flow. Comparison with BASF cone-plate data for N 1 shows that N 2/ N 1 lies in the range from −0.1 to −0.2. Values of η′ at temperatures in the range 0–40 ° C and values of angular frequency ω in the range 1–3600 s −1, obtained with a coaxial cylinder rheometer in which the inner cylinder oscillates along its axis, give satisfactory time-temperature superposition; values of η″, however, show small but significant deviations from time-temperature superposition. The curves η r( γ . r) and η′ r(ω r) intersect; the limiting value of ( N 1 - N 2) r/(2 γ . 2 r) obtained by extrapolation to low γ . r equals the value of G′ r/ω 2 r at low ω r. Oscillatory shear birefringence data (0–40 ° C, 5 s −1 < ω < 6280 s −1), obtained with a parallel plate apparatus in which one plate oscillates in its plane, show small but significant deviations from the equation n = A I + C p , where n and p denote the solution refractive index and stress tensors and A, C are ω-independent scalars. Solvent contributions were not subtracted from n or p .