as emigrants from the Soviet Union devastated vending donuts, throwing coins made of frozen water

[DARPA]

America, 50-60gg. the last century. One electric company has decided to establish in every home machine: throw a coin into the slot - the light is a certain time. No coins - there is no electricity. The principle is simple and primitive: the higher denomination coins, and hence the weight of the coin is, the longer the light is. Once a week came employee and took the coin. Everything was fine until one house (possibly lived emigrants from the Soviet Union?), In the machine turned out to be too little money. The calculation showed that enough money only for a couple of days of use of electricity. And so it was repeated for a long time, until it became clear that the electricity used by the residents every day! At the same time, foreign objects in the machine is not found traces of tampering was not there.

The secret was simple as two fingers ... They made molds for coins made of ice. Residents learned withdrawal schedule coins and two days before the withdrawal, beginning to use a gun fair! to cover their tracks, so to speak. That is - until it dries water. Still, the staff saw through this trick, corrosion coins rather, on the fly, left after drying of water on the surface of the coin. Perhaps if used distillirovonoy water, the chances of using this method increased for a longer period ....

Employees were forced to replace machines on conventional counters.