This hook represents a valuable and bimely rontrihutian t,o the chemical literature.
UNIT OPERATIONS OF CHEMICAL ENGINEERING
W. L. McCobe, Administrative Dean, Polytechnic Institute of Brooklyn, and I. L. Smith, Professor of Chemical E g i neering, Cornell University. McGrawHill Book Co., Ino., New York, 1956. ix 945 pp. 497 figs. 16 X 23.5 cm. $10.50.
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IN LATE 1855 appeared "Introduction to Chemical Enginoering" by V'. I,. Badger and J. T. Banchero. Tho secret was out. The writing team of Badger and McCabe that had produced the highly succeasfnl "Elements of Chemical Engincering" had gone their separate ways, each had selected a new co-author, and two new books would appear to replace the 1936 odition of "Elements." There was no doubt that Badger and Bnnchero had done a soccesaful job IJ. CHEM.Emc., 33, 88 (195611. How would McCnhe and Smit,h compare with this?
VOLUME 34, NO. 3, MARCH, 1957
A comparison of the tables of contents of "Elements of Chemical Engineering," "Introduction to Chemical Engineering," and "Unit Operatians of Chemical Engineering" shows essentially the same 16 chapters in each. IMcCebe and Smith have moved four chapters on minor unit operations of size reduction, handling of solids, mixing, and mechanical separations from the rear of the book to a place between fluid mechanics and flow of heat. The material on filtration now is included in mechanical separations. A general chapter on mass transfer precedes the chapterson ab.mrption, distillstion, leaching and extraction, and ot,her mass transfer operet,ions. If the tables of contents show the same chapters, how do the two books differ? Figures show "Introduction" has 753 psgqs and 419 illustmtions; "Unit 011eratlons" has 945 pages and 487 illustrations. I t is not sufficient to say therc are about 200 additional pages. The v i e w point of McCabe and Smith is definitely a t 8, higher level than Badger and Banr h ~ r o . "Unit Operations" has 8 chapter on Fluid Mechanics rather than Flow of Fluids, and the viewpoint is now more comprehensive and includes flow of campressible fluids. I n Flow of Heat, "Unit Operations" not. only gives more materid on conduction and convection but $80 discrmes unsteady state heat flow and gives much morc material on radiation. As we might expect, in Distillation much more cmphasis is placed on the McCabe-Thiele diagram, though
the Ponchan method is discuslied adeq~lstely. Each book has its separate field of greatest usefulness. Badger and Banchero undoubtedly will be used in unit operations courses given in the junior yom. McCabe and Smith will be used in senior Level courses or three semester courses. The l a ~ g e ramount of material, particularly equations for special sets of conditions, will be useful reference material which the student can find easily and grasp its signifionnce and limitations from the other material which he has studied. Because the McGraw-Hill Series in Chemical Engineering has an Editorial Advisarv Committee. there should be some action taken on nomenclature. SIcCahe and Smith have obviod>- tried to make some symbols ditkrent from Badger and Banehero, possibly for the snke of being different. The use of i for enthalpy is European practice and is also used in humidification calculations, hut it in different. from the h used in dist,illation calculations in other textbooks. Students are going to use several of the books concurrently, either as t,ests or references. Why cannot the Editarial Advisory Committee consider this problem and exert some influence over authors who want. to be different in matters of ~omenclnture? The $10.50 paid for hlrCahe and Smith compared to the 69.50 for Badger and Banchero is an extra dollar aell spent. (Conlinued on page A135)
I t buys 200 additional pages of tcxt rontaining 80 figures, and all is a t x higher level of viewpoint. These two Imoks will dominate the field of teaching of unit, operations of cbemicnl engineering. I
