While Thomas Adams was the first successful inventor and producer of a vending machine in the United States, there are many vending machines that pre-date his elsewhere.
Hero Ctesibius (sometimes referred to as Heron) of Alexandria documented the first vending machine in the published journal entitled Pneumatika in 62 A.D. This vending machine would accept a five-Drachma piece in exchange for a small supply of holy water in Egyptian temples. The machine worked on a balance system. When a coin was inserted, it tipped a balance, lifting a plug in the water urn and allowing a small amount of liquid to escape. When the coin had rolled into the collection bin inside the machine, the balance returned to normal, stopping the flow of water. By charging for sacrificial water, the temples could ensure that even when donations were low, they could still be well funded. The primitive nature of the machine was not a big problem in this arena, because church goers were fearful that the gods would punish them if they were to use slugs in the holy water machines.
Centuries later, around 1615, snuff and tobacco vendors became popular in England. This system required an honest customer, as it did not automatically vend a portion of tobacco. Instead, the device would open up displaying the entire contents of its product, leaving it up to the customer to take only what he or she paid for, and then closing it again before the next transaction could take place. Thus, these machines are referred to by the name of Honor Boxes. Often barmaids or other servicers were in charge of policing this transaction so that the top was closed again before the next customer came along.
In England in 1822, Richard Carlile invented a book vending machine. This particular machine had a dial that could be turned to a certain book title, and upon inserting the appropriate amount of money, the book would be dropped into a pick-up shelf in the lower half of the machine. The purpose of this machine was to avoid censorship laws which prohibited the selling of certain black-listed books. Carlile believed that if a machine sold the banned books, prosecution for this illegal activity would fail. Unfortunately for Carlile and his employees, this was not the case and he served jail time for selling the books indirectly through machines.
The first patented vending machine was developed by Simeon Denham of Yorkshire, England in 1857. His machine dispensed penny stamps and was relatively ineffective for the most part.
The first “commercially viable” vending machine was invented by Percival Everitt in 1883. It was a post card vending machine that Everitt installed in London. Regardless of its inconvenient size and weight (it was made of cast-iron and as tall as an average sized adult), it became quite popular and more than one hundred boxes were installed in London. An original feature developed by Everitt was that when machines were out of stock, they automatically closed the coin slot so no customers could lose their money.  Everitt continued to develop his machines, adding other features and adapting the machine for a few other products, such as stamps. Everitt also tried to thwart attempts to use slugs, by making the weighing scale in his machines more exact. He also placed machines in high traffic areas, such as near railroad stops, so that rail employees could help police the machines.
It was Everitt’s machine that sparked Thomas Adams’s interest in automatic vending. In fact, Adams obtained the “American patent rights” to Everitt’s penny scale machine and adapted it to sell his Tutti Frutti chewing gum. While their were other efforts to produce effective vending machines in the United States before Adams, foreigners took the foreground of this endeavor until Adams came into the picture in 1888.
 Kerry Segrave, Vending Machines: An American Social History, (Jefferson, NC: McFarland & Company, 200), 3.
 For more information on Hero and his various early inventions, see Drachmann, A.G., The Mechanical Technology of Greek and Roman Antiquity, (Madison, WI: University of Wisconsin), 1963.
 Michael Colmer, The Great Vending Machine Book (Chicago: Contemporary Books, 1977), 1.
 Segrave, 4.
 Colmer, 2-3.
 Colmer, 2.
 Segrave, 5.
 Martin V. Marshall, Automatic Merchandising; a study of the problems and limitations of vending, (Boston, MA: Harvard University, 1954), 6.
 Segrave, 5.
 Ibid., 5
 Colmer, 3
 Ibid. This technology did not transfer over to the United States immediately, as Charles W. Goldsmith patented this feature in 1896.
 Ibid., 4-5. Later, Everitt’s machine was adapted to be used as a postage stamp vendor.
 Marshall, 6.