An experimental study of the enthalpy of steam

The measurements on the total heatf of steam by the condenser method carried out between the years 1931 and 1940 are described. The apparatus was adapted from that used for the measurement of the saturation pressure of steam (Egerton & Callendar 1932). Part I deals with the investigation of the sources of error, particularly the heat-loss correction, as a result of which the modifications in the apparatus described in part II were made. The final measurements, amounting to about 400, range from 10 to 225 Kg/cm2 and from 200 to 600 °C, at intervals of about 25 Kg/cm2 and 25 °C. The smoothed results are also given in bars, and are considered to lie within about 1 part in 1500 of the true values