It is a privilege to be asked to introduce this important work. Such a book has long been needed. Industrial manipulators and robots have caught the attention of the general public and become very fashionable in the last few years. The casual reader of current newspapers and magazit: les or the viewer of television and films might easily conclude that the development of mechanical hands, arms and legs or other mobility devices has progressed rapidly in only the last few years. Most people are unaware of the gradual orderly succession of creative designs and painstaking refinements which have been produced over a greater number of years. That story is carefully described in this volume, together with diagrams and photographs which document in detail this elegant phase in the history of machine design. This volume together with Volume 3A constitute the most complete and comprehensive work on manipulators and teleoperators. Jean Vertut and Philippe Coiffet are well known not only as authors but also as engineers who have produced some of the finest devices in the world. Of course for the complete history of manipulators and teleoperators one must look back to the artisans who crafted the delightful clock works, mechanical puppets and toys before and during the Renaissance."