Interesting tools serve to help us understand our surroundings (pl.: perpetuum mobile, pop pop boat, mirascope, yoyo, holey ball, scuba diver)
These items swing and balancing for a long time, if we once bump them.
These toys are on the basic of feature of magnet material.
spinning tops, yoyos, humming top, giroscope,
These optical items swindle our eyes, make us happy, and enchant us.
Steam-engine and other energies
What are move these items? How we can play with a leaky paper ball? why drunky is the glass bird? We can answer for these questions with help of these toys.