H~TIZ.~OGENEITY is nn inevitable feature of an edition like Advances in Chemical Engineering, not only with respect to the subjects treated, but also regarding the approach by the different authors. Also in this volume it appears that the aim to present a "critical summary of recent work " (quoted from the editors' preface) may be interpreted rather freely.
Evidently, the task of the reviewer is to write a number of short reviews 6rst and to sum them up, if possible, in the end.
J. W. WESTWATEB finishes his monograph (the first part of which appeared in
Advances of Chemical Engineering, Volume I) on the Boiling of Liquids (p. l-8, 88 references) with chapters on transition boiling, illm boiling, boiling of subcooled liquids and bumping during boiling. Except for the pure ilhn boiling, these phenomena have not been successfully explained by theory and the experimental material is still very incomplete.. This is reflected in the text which is clearly written and well illustrated, but has to be mostly descriptive. Pages 88-80 contain a paper on Automutk Process Contd (Ss references) by E. F. JOHNSON. Control is introduced as a basic concept of chemical engineering and control problems are treated analytically, mostly by using the frequency response method. This paper has the