We take an opportunity to present this standard treatise entitled as “Theory of Machines” to the students of Degree, Diploma and A.M.I.E. (I) classes in M.K.S. and S.I. units. The object of this book is to present the subject matter in a most concise, compact, to-the-point and lucid manner.
While writing the book, we have continuously kept in mind the examination requirements of the students preparing for U.P.S.C. (Engg. Services) and A.M.I.E. (I) examinations. In order to make this volume more useful for them, complete solutions of their examination papers up to 1975 have also been included. Every care has been taken to make this treatise as self-explanatory as possible. The subject matter has been amply illustrated by incorporating a good number of solved, unsolved and well graded examples of almost every variety. Most of these examples are taken from the recent examination papers of Indian and foreign universities as well as professional examining bodies, to make the students familiar with the type of questions, usually set in their examinations. At the end of each chapter Highlights have been added, which summarise the main topics discussed in the chapter for quick revision before the examination. After the highlights, a few exercises have been added for the students to solve them independently. Answers to these problems have been provided, but it is too much to hope that these are entirely free from errors. In short, it is earnestly hoped that the book will earn appreciation of the teachers and students alike.

The present multicolour edition has been thoroughly revised and brought up-to-date. Multicolour pictures have been added to enhance the content value and to give the students an idea of what he will be dealing in reality, and to bridge the gap between theory and practice. The mistakes which had crept in, have been eliminated. We wish to express our sincere thanks to numerous professors and students, both at home and abroad, for sending their valuable suggestions and recommending the book to their students and friends. We hope, that they will continue to patronise this book in the future also.