This book is the revised 1941 mid-century guide on the basic principles of Shop from the prestigious Henry Ford Trade School, first published in 1934. The book was used by students attending Shop Theory classes and focusses on the historical development, principles of construction, and use, care, and operation of hand tools, precision tools, and the usual toolroom machines and equipment. The lesson sheet method of instruction, supplemented by lecture and discussion, is used. This compilation of the sheets, which was revised and brought up to date, should prove valuable as a reference for students and shop instructors.