One day on a whim the father of the house and the children his and the neighbors’ decided to build a tree house. They scouted the trees all over our backyard for the most suitable one and decided on a 6 years old oak tree. It has branches big enough to support their tree house and it is low enough for the father’s comfort. One pair of eyes is eyeing the tree doubtfully though and the pair of eyes squeaked “We have to visit our tree house two at a time. It can’t carry all of us. It’s not the Hulk.” Three voices piped their agreement “Yeah…”
Construction began happily and enthusiastically the next weekend. All the other kids’ fathers joined. Moms brought snacks and lunches the construction began to take an air of a party. They saw, hammered and measured steadily that the tree house was almost finished before they stopped for lunch. They took to the work immediately after eating while the kids were tucked for siesta. By three o’ clock all activity stopped. Huddled around the hand rails they were murmuring their puzzlement why the railings won’t stick to the stairs. Some of their posts were shorter than the others.
One father disappeared and came back carrying something inside a rucksack. He brought that something out of the rucksack and voila appeared three manual clamps used by carpenters. They clamp the handle and posts railings to the stairs on three points with the manual clamps, dipped the nails into a tub of wood glue and hammered it into the posts then left the clamp on for a week. Weekend came they approach their tree house almost reverently and took the clamps off. Taa dah! The railings stick. Well thanks to manual clamping systems that were invented many years ago almost all kinds of works requires some kind of clamping system. Mechanical, construction, electrical and wood working each work will need a clamp sooner and clamps of all kinds were manufactured for each of their requirements.