Faced with the prospect of machining a gear or gears for a project, many model engineers will be discouraged and will turn elsewhere for their next model. This need not be so, for the principles underlying gear cutting and many other aspects of engineering where an accurate division of circles is required are explained in depth in this book. Radial work on a metalworking lathe, such as the cutting of gearwheels or the drilling of holes on a set radius, calls for a method of precisely spacing the cuts. This skill is known as Dividing. The principles underlying this aspect of engineering are explained in depth in this book. It covers the subject of Dividing, dealing with the many methods that can be adopted: from simple applications without specialised equipment to the use of a semi-universal dividing head and a rotary table. The mathematical aspects of dividing are also covered but at a level that will be understood easily by a model engineer. Dividing equipment is relatively expensive, so two fully-detailed designs are included for dividing heads: a basic unit and the equivalent of a commercial semi-universal head.