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The elements of machine design
856
BOOK REVIEWS.
[J. F. I.
TECHNICAL MECHANICS, STATICS, KINEMATICS, KINETICS. By Edward R. Maurer, Professor of Mechanics in the University of Wisconsin, and Raymond J. Roark, Assistant Professor of Mechanics in the University of Wisconsin. Fifth Edition, rewritten, xii + 354 pages, 6 " × 9", cloth, 559 illustrations. New York, John Wiley and Sons, Inc., 1925. Price, $3,5 0 net. The modern college course in engineering imposes a severe stress upon the mental endurance of the student, and it is most desirable that the subjects prescribed be presented in such a manner as to effect the greatest economy of effort in their prosecution. The time-element is an important factor, the student must dwell upon the work he is doing at some length in order to acquire a real familiarity with it. It is in the reduction to a minimum of these inevitable periods of reflection that the value of a text-book is greatly amplified. This important matter which is secondary only to the technical value of the subjectmatter, the authors have kept well in mind. The work may be properly described as a formal text on the elements of mechanics with applications to engineering problems, The treatment is deductive and rigorous without oppressive formality, and well-illustrated detailed explanations illuminate the discussions of the various theorems and give them an interest which they would otherwise lack. At the end of each section an illustrative example is given. These are worked out in detail with references to the text and are arranged in the good form suitable to serve as a model for the student to apply to his own work. Such examples are most helpful in insuring an accurate and ready appreciation of the full significance of a theorem. Drill-problems do not appear in the text, but a large number, well illustrated, are provided in an appendix at the end of the volume. Graphs and tabulated computations are freely used. The extensive employment of the latter emphasizes the value of this simple clerical device in keeping track of the various elements and successive steps of computations of considerable length. In this comprehensive collection of mechanical theorems, the vibration of a mass acted upon by a force which varies as a function of its distance from a central point for some reason has been ignored, although its elementary treatment need not transcend the presupposed knowledge of trigonometry and simple calculus; vibration problems are of timely interest. The character and execution of the work reflect credit alike upon the authors and publishers. LUCIEN E. PICOLET. THE ELEMENTS OF MACHII,,'E DESI(;N. By S. J. Berard, Assistant Professor of Drawing and Machine Design, Brown University, and E. O. Waters, Assistant Professor of Machine Design, Sheffield Scientific School, Yale University. 323 pages, 6" × 9", cloth, 244 illustrations. New York, D. Van Nostrand Company. Price, $2.50 net. For many years technical periodicals and the publications of engineering societies have recorded an uninterrupted flow of contributions to the art of machine construction and these sources, as well as compilations in book-form which have appeared from time to time. constitute an abundant store of information to which nothing need be added to meet the technical requirements
june, I925. ]
BOOK R E V I E W S .
857
of current practice in the art. The work in hand is a text on the methods of proportioning machine parts which have been drawn from this copious source. It has been prepared for the use of students in engineering courses and others, properly qualified, who desire to become machine designers. W i t h that object, the authors have shown discrimination in their choice of subject-matter as representative of approved practice and wisdom in its arrangement. The first three chapters, covering forty-two pages, are devoted to tlae more commonly used data on structural elements, section moduli, typical beams, etc., and an excellent code of practice in the preparation and execution oi a design, and of checking drawings. Each of the remaining twenty-five chapters with the exception of the last treats of some machine part of which the various types of representative practice are described and formulated. These are illustrated by excellent line-cuts reproduced from equally workmanlike drawings, and by half-tone cuts. The last chapter treats of draftingroom systems. With each topic an illustrative numerical example is given, worked out in carefully arranged detail, which may well serve as a model to the student in arranging his notes as well as clarifying the explanations. A list of references is given at the end of each chapter. Among some of the notable features included in the text may be mentioned the account on limits, tolerance and allowance, the analysis of rivetted joints based on the A.S.M.E. Boiler Code and the adoption of the Lewis formula for the strength of gear teeth. In the well-balanced section on gearing no mention appears to be made of the metric notation for diametral pitch. It is a relatively small matter, but since it is used by American manufacturers it might properly be mentioned. Again the inclusion of the open-belt method of design of cone-pulleys would be welcome to some users of a book of this kind. The omission of such topics as machine frames, thick cylinders, flat covers and springs will prove disappointing to a large number who will naturally expect to find them under such a broad title as " machine design." The typographical work throughout is of a high order of excellence. LUCIEN E. PICOLET. RECENT PROGRESS IN ENGINEERING PRODUCTION. By C. M. Linley. 340 pages, illustrations, plates, 8vo. New York, D. Van Nostrand Company, 1925. Price, $Io. Manufacturing industries in recent years have adopted many of the methods for securing accuracy previously found only in the physical laboratory, and pieces of apparatus and not a few of the requirements in methods employed found in many modern shops were never dreamed of by the old-time mechanic. In contrast with former conservation, managers of up-to-date shops, particularly those devoted to large-scale production, are keenly appreciative of the possibilities offered by the contributions of the scientific laboratory. It is therefore essential that the manager who would have his shop at the highest point of efficiency or the engineer who would plan such a shop, should be a u c o u r a n t with those "vulgarized " laboratory appliances and methods which have become available for commercial use. It is with these modern appliances and methods that the author deals in the forty-one chapters of his book. Each chapter is devoted to some particular
BOOK REVIEWS.
[J. F. I.
TECHNICAL MECHANICS, STATICS, KINEMATICS, KINETICS. By Edward R. Maurer, Professor of Mechanics in the University of Wisconsin, and Raymond J. Roark, Assistant Professor of Mechanics in the University of Wisconsin. Fifth Edition, rewritten, xii + 354 pages, 6 " × 9", cloth, 559 illustrations. New York, John Wiley and Sons, Inc., 1925. Price, $3,5 0 net. The modern college course in engineering imposes a severe stress upon the mental endurance of the student, and it is most desirable that the subjects prescribed be presented in such a manner as to effect the greatest economy of effort in their prosecution. The time-element is an important factor, the student must dwell upon the work he is doing at some length in order to acquire a real familiarity with it. It is in the reduction to a minimum of these inevitable periods of reflection that the value of a text-book is greatly amplified. This important matter which is secondary only to the technical value of the subjectmatter, the authors have kept well in mind. The work may be properly described as a formal text on the elements of mechanics with applications to engineering problems, The treatment is deductive and rigorous without oppressive formality, and well-illustrated detailed explanations illuminate the discussions of the various theorems and give them an interest which they would otherwise lack. At the end of each section an illustrative example is given. These are worked out in detail with references to the text and are arranged in the good form suitable to serve as a model for the student to apply to his own work. Such examples are most helpful in insuring an accurate and ready appreciation of the full significance of a theorem. Drill-problems do not appear in the text, but a large number, well illustrated, are provided in an appendix at the end of the volume. Graphs and tabulated computations are freely used. The extensive employment of the latter emphasizes the value of this simple clerical device in keeping track of the various elements and successive steps of computations of considerable length. In this comprehensive collection of mechanical theorems, the vibration of a mass acted upon by a force which varies as a function of its distance from a central point for some reason has been ignored, although its elementary treatment need not transcend the presupposed knowledge of trigonometry and simple calculus; vibration problems are of timely interest. The character and execution of the work reflect credit alike upon the authors and publishers. LUCIEN E. PICOLET. THE ELEMENTS OF MACHII,,'E DESI(;N. By S. J. Berard, Assistant Professor of Drawing and Machine Design, Brown University, and E. O. Waters, Assistant Professor of Machine Design, Sheffield Scientific School, Yale University. 323 pages, 6" × 9", cloth, 244 illustrations. New York, D. Van Nostrand Company. Price, $2.50 net. For many years technical periodicals and the publications of engineering societies have recorded an uninterrupted flow of contributions to the art of machine construction and these sources, as well as compilations in book-form which have appeared from time to time. constitute an abundant store of information to which nothing need be added to meet the technical requirements
june, I925. ]
BOOK R E V I E W S .
857
of current practice in the art. The work in hand is a text on the methods of proportioning machine parts which have been drawn from this copious source. It has been prepared for the use of students in engineering courses and others, properly qualified, who desire to become machine designers. W i t h that object, the authors have shown discrimination in their choice of subject-matter as representative of approved practice and wisdom in its arrangement. The first three chapters, covering forty-two pages, are devoted to tlae more commonly used data on structural elements, section moduli, typical beams, etc., and an excellent code of practice in the preparation and execution oi a design, and of checking drawings. Each of the remaining twenty-five chapters with the exception of the last treats of some machine part of which the various types of representative practice are described and formulated. These are illustrated by excellent line-cuts reproduced from equally workmanlike drawings, and by half-tone cuts. The last chapter treats of draftingroom systems. With each topic an illustrative numerical example is given, worked out in carefully arranged detail, which may well serve as a model to the student in arranging his notes as well as clarifying the explanations. A list of references is given at the end of each chapter. Among some of the notable features included in the text may be mentioned the account on limits, tolerance and allowance, the analysis of rivetted joints based on the A.S.M.E. Boiler Code and the adoption of the Lewis formula for the strength of gear teeth. In the well-balanced section on gearing no mention appears to be made of the metric notation for diametral pitch. It is a relatively small matter, but since it is used by American manufacturers it might properly be mentioned. Again the inclusion of the open-belt method of design of cone-pulleys would be welcome to some users of a book of this kind. The omission of such topics as machine frames, thick cylinders, flat covers and springs will prove disappointing to a large number who will naturally expect to find them under such a broad title as " machine design." The typographical work throughout is of a high order of excellence. LUCIEN E. PICOLET. RECENT PROGRESS IN ENGINEERING PRODUCTION. By C. M. Linley. 340 pages, illustrations, plates, 8vo. New York, D. Van Nostrand Company, 1925. Price, $Io. Manufacturing industries in recent years have adopted many of the methods for securing accuracy previously found only in the physical laboratory, and pieces of apparatus and not a few of the requirements in methods employed found in many modern shops were never dreamed of by the old-time mechanic. In contrast with former conservation, managers of up-to-date shops, particularly those devoted to large-scale production, are keenly appreciative of the possibilities offered by the contributions of the scientific laboratory. It is therefore essential that the manager who would have his shop at the highest point of efficiency or the engineer who would plan such a shop, should be a u c o u r a n t with those "vulgarized " laboratory appliances and methods which have become available for commercial use. It is with these modern appliances and methods that the author deals in the forty-one chapters of his book. Each chapter is devoted to some particular