The Turk was supposedly a chess-playing automaton; that is, a machine built to play a game of chess. It was first built in 1769 and it remained in operation until its destruction due to fire in 1854.
The Turk was developed in Vienna in 1769 by Baron Wolfgang von Kempelen, an engineer and polymath, for the amusement of the Roman empress Maria Theresa. He presented it for the first time in 1770, astounding the court at Vienna.
The structure was primarily a finely crafted maplewood cabinet, mounted on wheels and measuring about 4 feet long, 3½ feet high, and 2 feet deep, with a chessboard inlaid on top. At it sat a mannequin, a mustachioed figure dressed in a cloak and a turban, hence the name, "the Turk." Opening the doors in the cabinet, the interior showed gears and other machinery. Drawing aside the Turk's garments, the figure is shown to be a purely mechanical thing. With a clever master of ceremonies making the demonstration, it easily appeared as though no living thing much larger than a mouse could possibly be hidden inside the cabinet or mannequin.
Of course, this is a mere illusion. In a small room behind the gearwork, lit by candle, an expert chess player would sit. Through some technique involving the operation of the device (the exact operation is unknown, as the Baron never revealed the machinery, and the machine was destroyed in 1854), the player hidden inside the machine would respond to moves by the human player by instructing the device to move another piece. In essence, it was a well constructed piece moving device.
In order for the visual effect to work, though, there wasn't much space inside the Turk for players to sit, and to maintain the illusion, a good player had to be inside. A number of different players, essentially every master-level player in Europe that was of small stature, were employed to sit inside the machine, operating it.
The Baron toured Europe with the machine throughout the 1770s and 1780s, charging many admission prices to make a move against the machine, and more to play a game against it. In 1784, it was installed in London, where visitors were charged 5 shillings to play against it.
The Baron passed away in 1804, and the Turk was bought by a Bavarian musician, Johann Maelzel, who took it on tour throughout Europe again. Napoleon himself played a game against the machine in 1809. In 1826, Maelzel shipped the machine to the United States and toured the country with it. When Maelzel died in 1837, it was bought and sold among several carnival owners, eventually winding up in the Chinese Museum in Philadelphia, where it was destroyed by fire in 1854.
Many stories were told about the Turk in its day, ranging from the plausible to the fantastic. One common story was that there was only one person ever inside the Turk, a man named Warousky, who was a soldier who had his legs blown off during a war. Another tale is that a dwarf of very small stature actually sat inside the mannequin, making the moves, and that one was actually playing a dwarf chess master. It should be noted that with careful observation, one could realize that there was some sort of hoax going on, but the details remain a mystery to this day.
The Turk is one of the most clever hoaxes of all time, one that P.T. Barnum would be proud of.