The class 7 pupils entering adolescence and developing ever new facilities of insight of their own growth that connects them to the world of mechanics. Often this time is characterised by, the reef knot and the bowline. These knots originated in the pre-industrial age where ropes were important in hoisting sails, hitching boats and animals, lashing loads onto wagons etc.

Knots, pulleys and levers all emerged in pre-industrial times when we used hands and animals to get the job done. This Main Lesson builds on the ideas explored in the “Man and Animal” Main Lesson of Class Four where children discovered the speciality of various animals and the tools that we humans beings have developed to become specialists as well. Taking up this thread in Class Seven the pupils discover that one of the most versatile tools that man has invented is the lever and mechanics starts with the lever, this multi-purpose tool can be divided into three classes. Through experiments which explore the way levers work, they discover the Law of Leavers and then apply this knowledge to the inclined plan and screw. This leads on to exploring the meaning of thread, pitch and torque.

The lesson brings the class an experience of pulleys and how to obtain a “mechanical advantage” to lift a weight that much heavier than ones own body weight. It is fascinating to observe the development of thinking in children of this age. Mechanical advantage is a new thought for them and it is a revelation that this is the way human beings think.

This main lesson prepares the pupil for the encounter with the four industrial revolutions which will be studied in High School. The first industrial revolution, presented in Class 8 explores water, steam and transport. The second industrial revolution studied in Class 9 explores communication, the third in Class 11, the electro magnetic spectrum, radio activity and nuclear power, and the fourth in Class 12, the digital revolution. This involves the pupil not only knowing how to use the computer but also how to build one and program it. To develop a true mortality the pupil should not just know how to use a machine like a computer but should know how it works.