Very High-Resolution Heat-Capacity Measurements near the Lambda Point of Helium

New measurements of the heat capacity of a sample of helium 3 mm high are reported which extend to within 5×{}10^-8 deg of the lambda transition at the vapor pressure. From an analysis of the results allowing for the effect of gravity, the values -0.0127±{} 0.0026 (2σ) for the exponent α (=α^') and 1.058±{}0.004 for the leading singularity ratio AA^' are obtained. These values are in closer agreement with the theoretical predictions than those reported previously.