From Introduction: "This bulletin originally was planned as a second revision of the first member of this series, the first revision (249) having appeared in 1936; however, because of requests for the explanatory, section of the first bulletin from those teaching thermodynamics, it was decided to combine the information in the first bulletin and its revision with the data that have appeared since 1935 and to repeat the explanatory material in somewhat more detail. The purpose of this bulletin is therefore to give the available values of the entropies at 298.1 degrees K. of the elements and inorganic compounds, together with enough explanation of the methods employed in calculating entropies to make the results comprehensible."