The vending machine is usually viewed as an ultra modern machine, and in its present form it is. However, as early as 1857 a stamp vending machine was introduced in London, England. Lacking in mechanical sophistication the machine could be fooled into dispensing stamps by inserting almost any object of roughly the correct shape and weight.
This shows one of the most vexing problems facing the designers of modern vending machines, namely, coin checking. This has reached very advanced levels, it is almost impossible to fool the modern vending machine with anything but a real coin of the correct denomination.
Vending machines are usually associated with the sale of food and drink. Packaged items such as foodstuffs and canned cold drinks are very easy to vend. Multi-select hot drink vending machines are the most difficult to design. In the hot drinks vendor, a tank of water is kept constantly hot. When coins of the correct value are inserted and a selection made, the machine will drop an empty cup into the vending hatch, the selected powder-based ingredient (coffee, tea, soup, etc.) is then measured and dispensed into the cup. Boiling water from the tank is pumped into the cup for a predetermined time until the cup is full. The operator lifts the vend hatch and removes the piping hot drink.
