How to build a spring-well


This spring-well is also known as Heron spring-well and it was invented on antiquity. During centuries it suffers a lot of improvements so in our days you may easily build a spring-well using recycled and some other cheap materials.
First of all you will need two big plastic bottles of juice. Open one of them, drink, and continue to read. As you can see in the attached drawing you will need about 3m of rubber tubes as you use at your aquarium, some waterproof glue as acrylic silicone. If you don’t have this stuff around you is time for a trip at a supermarket, but first of all don’t forget to drink the whole bottle of juice. Now we have an empty bottle the other must be empty in the shortest possible time. We have the rubber tubes, the glue we need only a plastic bowl and a nozzle whence can be a part of a ball pen suited with the rubber tube hole. Make appropriate holes into the bottles slip in the rubber tubes add enough glue to be waterproof, fill the bottles with water (only half each one), drill the plastic bowl and insert the rubber tubes add glue , attach the nozzle. Put one bottle on a chair and the other one on the floor (about 1m between them), put water on the bowl in such a manner that only the nozzle to be out of the water. Enjoy it. When the spring-well stops just reverse the bottles position and put the nozzle on the other tube.You will see that the high of the water jet depend only by the level difference between this two bottles

Make a Boomerang


This weapon is the most outstanding technical achievement of primitive men. You can make your own boomerang in a very simple way. As is shown in the drawing you may cut the shape of the boomerang from a postcard, each arm has 5cm long and 1cm width. Grab it by the middle between the tip of the thumb and the pointer and hit it in a slightly upward direction. Enjoy it!

The secret of the wheel

Fix on the upper part of a wheel a piece of paper. You will see a very curious phenomenon when the wheel is moving: as long the piece of paper is on the upper part of the wheel you can’t see it distinct but when it is on bottom part of the wheel you can see it very well, it seem that the upper part of the wheel is moving faster than the bottom part. As it shows in the drawing when the wheel is rolling, the distance streamed by the upper part of the wheel is bigger than the distance streamed by the bottom part of the wheel.
The explanation is very common: Each point of the wheel has two types of motions; a motion of translation with its axle, and a motion of rotation around its axle. On the upper part of the wheel this two types of motion have the same direction but on the bottom part of the wheel they have opposite directions