Letters on Natural Magic
(extract) - Sir David Brewster (1781-1868)
Ingenious as all these machines are, they sink into insignificance when compared with the automaton chess-player, which for a long time astonished and delighted the whole of Europe. In the year 1769, M. Kempelen, a gentleman of Presburg in Hungary, constructed an automaton chess-player, the general appearance of which is shown in the annexed figures. The chess-player is a figure as large as life, clothed in a Turkish dress sitting behind a large square chest or box three feet and a half long, two feet deep, and two and a half high. The machine runs on casters, and is either seen on the floor when the doors of the apartment are thrown open, or is wheeled into the room previous to the commencement of the exhibition. The Turkish chess-player sits on a chair fixed to the square chest. His right arm rests on the table, and in the left he holds a pipe, which is removed during the game, as it is with this hand that he makes the moves. A chess-board, eighteen inches square, and bearing the usual number of pieces is placed before the figure.
The exhibitor then announces to the spectators his intention of shewing them the mechanism of the automaton. For this purpose he unlocks the door A, Fig. 61, and exposes to view a small cupboard lined with black or dark coloured cloth, and containing cylinders, levers, wheels, pinions, and different pieces of machinery, which have the appearance of occupying the whole space. He next opens the door B, Fig 62, at the back of the same cupboard and, holding a lighted candle at the opening, he still farther displays the enclosed machinery to the spectators, placed in front of A, Fig. 61. When the candle is withdrawn, the door B is then locked; and the exhibitor proceeds to open the drawer G G, Fig. 6l, in front of the chest. Out of this drawer he takes a small box of counters, a set of chess-men, and a cushion for the support of the automaton's arm, as if this was the sole object of the drawer.
The two front doors C, C, of the large cupboard, Fig. 61, are then opened, and at the back-door D of the same cupboard, Fig. 62, the exhibitor applies a lighted candle, as before, for the purpose of shewing its interior, which is lined with dark cloth like the other, and contains only a few pieces of machinery. The chest is now wheeled round, as in Fig. 62: The garments of the figure are lifted up, and the door E in the trunk, and another door F, in the thigh, are opened, the doors B and D having been previously closed. When this exhibition of the interior of the machine is over, the chest is wheeled back into its original position on the floor. The doors A, C, C, in front, and the drawer G, G, are closed and locked, and the exhibitor, after occupying himself for some time at the back of the chest, as if he were adjusting the mechanism, removes the pipe from the hand of the figure, and winds up the machinery.
The automaton is now ready to play, and when an opponent has been found among the company, the figure takes the first move. At every move made by the automaton, the wheels of the machine are heard in action; the figure moves its head, and seems to look over every part of the chess-board. When it gives check to its opponent, it shakes its head thrice, and only twice when it checks the Queen. It likewise shakes its head when a false move is made, replaces the adversary's piece on the square from which it was taken, and takes the next move itself. In general, though not always, the automaton wins the game.
During the progress of the game, the exhibitor often stands near the machine, and winds it up like a clock after it has made ten or twelve moves. At other times he went to a corner of the room, as if it were to consult a small square box, which stood open for this purpose.
The chess-playing machine, as thus described, was exhibited after its completion in Presburg, Vienna, and Paris, to thousands, and in 1783 and 1784 it was exhibited in London and different parts of England, without the secret of its movements having been discovered. Its ingenious inventor, who was a gentleman and a man of education, never pretended that the automaton itself really played the game. On the contrary, he distinctly stated, "that the machine was a bagatelle which was not without merit in point of mechanism, but that the effects of it appeared so marvellous only from the boldness of the conception, and the fortunate choice of the methods adopted for promoting the illusion."
Upon considering the operations of this automaton, it must have been obvious that the game of chess was performed either by a person enclosed in the chest, or by the exhibitor himself. The first of these hypotheses was ingeniously excluded by the display of the interior of the machine, for as every part contained more or less machinery, the spectator invariably concluded that the smallest dwarf could not be accommodated within, and this idea was strengthened by the circumstance, that no person of this description could be discovered in the suite of the exhibitor. Hence the conclusion was drawn, that the exhibitor actuated the machine either by mechanical means conveyed through its feet, or by a magnet concealed in the body of the exhibitor. That mechanical communication was not formed between the exhibitor and the figure, was obvious from the fact, that no such communication was visible, and that it was not necessary to place the machine on any particular part of the floor. Hence the opinion became very prevalent that the agent was a magnet; but even this supposition was excluded, for the exhibitor allowed a strong and well armed loadstone to be placed upon the machine during the progress of the game: Had the moving power been a magnet, the whole action of the machine would have been deranged by the approximation of a loadstone concealed in the pockets of any of the spectators.
As Baron Kempelen himself had admitted that there was an illusion connected with the performance of the automaton, various persons resumed the original conjecture, that it was actuated by a person concealed in its interior, who either played the game of chess himself, or performed the moves which the exhibitor indicated by signals. A Mr J. F. Freyhere of Dresden published a book on the subject in 1789, in which he endeavoured to explain, by coloured plates, how the effect was produced; and he concluded, "that a well-taught boy, very thin and tall of his age, (sufficiently so that he could be concealed in a drawer almost immediately under the chess-board) agitated the whole".
In another pamphlet which had been previously published at Paris in 1785, the author not only supposed that the machine was put in motion by a dwarf, a famous chess-player, but he goes so far as to explain the manner in which he could be accommodated within the machine. The invisibility of the dwarf when the doors were opened was explained by his legs and thighs being concealed in two hollow cylinders, while the rest of his body was out of the box, and hid by the petticoats of the automaton. When the doors were shut the clacks produced by the swivel of a ratchet-wheel permitted the dwarf to change his place and return to the box unheard; and while the machine is wheeled about the room, the dwarf had an opportunity of shutting the trap through which he passed into the machine. The interior of the figure was next shown, and the spectators were satisfied that the box contained no living agent.
Although these views were very plausible, yet they were never generally adopted; and when the automaton was exhibited in Great Britain in 1819 and 1820, by M. Maelzel, it excited as intense an interest as when it was first produced in Germany. There can be little doubt, however, that the secret has been discovered; and an anonymous writer has shown in a pamphlet, entitled "An attempt to analyse the automaton chess-player of M. Kempelen," that it is capable of accommodating an ordinarily sized man; and he has explained in the clearest manner how the inclosed player takes all the different positions, and performs all the motions which are necessary to produce the effects actually observed. The following is the substance of his observations:
The drawer G G when closed does not extend to the back of the chest, but leaves a space O, behind it, (See Fig. 69, 70, and 71,) fourteen inches broad, eight inches high, and three feet eleven inches long. This space is never exposed to the view of spectators. The small cupboard seen at A is divided into two parts by a door or screen I, Fig. 66, which is moveable upon a hinge, and is so constructed that it closes at the same instant that B is closed. The whole of the front compartment as far as I is occupied with the machinery H. The other compartment behind I is empty, and communicates with the space O behind the drawer, the floor of this division being removed. The back of the great cupboard C C is double, and the part P Q, to which the quadrants are attached, moves on a joint Q, at the upper part, and forms when raised an opening S, between the two cupboards, by carrying with it part of the partition R, which consists of cloth tightly stretched. The false back is shown closed in Fig. 69, while Fig. 70 shows the same back raised, so as to form the opening S between the chambers.
When the spectator is allowed to look into the trunk of the figure by lifting up the dress, as in Fig. 70, it will be observed that a great part of the space is occupied by an inner trunk N, Fig. 70, 71, which passes off to the back in the form of an arch, and conceals from the spectators s portion of the interior. This inner trunk N opens and communicates with the chest by an aperture T, Fig. 72, about twelve inches broad and fifteen high. When the false back is raised the two cupboards, the trunk N, and the space O behind the drawer, are all connected together.
The construction of the interior being thus understood, the chess-player may be introduced into the chest through the sliding panel U, Fig. 69. He will then raise the false back of the large cupboard, and assume the position represented by the shaded figure in Fig. 63 and 64. Things being in this state, the exhibitor is ready to begin his process of deception. He first opens the door A of the small cupboard, and from the crowded and very ingenious disposition of the machinery within it, the eye is unable to penetrate far beyond the opening, and the spectator concludes without any hesitation, that the whole of the cupboard is filled, as it appears to be, with similar machinery. This false conclusion is greatly corroborated by observing the glimmering light which plays among the wheel work when the door B is opened, and a candle held at the opening. This mode of exhibiting the interior of the cupboard satisfies the spectator also that no opaque body capable of holding or concealing any of the parts of a hidden agent is interposed between the light and the observer. The door B is now locked and the screen I closed, and as this is done at the time that the light is withdrawn it will wholly escape observation.
The door B is so constructed as to close by its own weight, but as the head of the chess-player will soon be placed very near it, the secret would he disclosed if, in turning round, the chest door should by any accident fly open. This accident is prevented by turning the key, and, lest this little circumstance should excite notice, it would probably be regarded as accidental, as the keys were immediately wanted for the other locks.
As soon as the door B is locked, and the screen I closed, the secret is no longer exposed to hazard, and the exhibitor proceeds to lead the minds of the spectators still farther from the real state of things. The door A is left open to confirm the opinion that no person is concealed within, and that nothing can take place in the interior without being observed.
The drawer G G is now opened, apparently for the purpose of looking at the chess-men, cushion and counters which it contains; but the real object of it is to give time to the player to change his position, as shown in the annexed figure, and to replace the false back and partition preparatory to the opening of the great cupboard. The chess- player, as the figure shows, occupies with his body the back compartment of the small cupboard, while his legs and thighs are contained in the space O, behind the drawer G G, his body being concealed by the screen I, and his limbs by the drawer G G.
The great cupboard C C is now opened, and there is so little machinery in it that the eye instantly discovers that no person is concealed in it. To make this more certain, however, a door is opened at the back, and a lighted candle held to it, to allow the spectators to explore every corner and recess.
The front doors of the great and small cupboard being left open, the chest is wheeled round to show the trunk of the figure, and the bunch of keys is allowed to remain in the door D, as the apparent carelessness of such a proceeding will help to remove any suspicion which may have been excited by the locking of the door B.
When the drapery of the figure has been raised, and the doors E and F in the trunk and thigh opened, the chest is wheeled round again into its original position, and the doors E and F closed. In the meantime the player withdraws his legs from behind the drawer, as he cannot so easily do this when the drawer G G is pushed in.
In all these operations, the spectator flatters himself that he has seen in succession every part of the chest, while in reality some parts have been wholly concealed from his view, and others but imperfectly shown, while at the present time nearly half of the chest is excluded from view.
When the drawer G G is pushed in, and the doors A and C closed, the exhibitor adjusts the machinery at the back, in order to give time to the player to take the position shown in a front view in Fig. 66, and in profile in Fig. 67. In this position he will experience no difficulty in executing every movement made by the automaton. As his head is above the chess-board, he will see through the waistcoat of the figure, as easily as through a veil, the whole of the pieces on the board, and he can easily take up and put down a chess man without any other mechanism than that of a string communicating with the finger of the figure. His right hand being within the chest may be employed to keep in motion the wheel-work for producing the noise which is heard during the moves, and to perform the other movements of the figure, such as that of moving the head, tapping on the chest, &c.
A very ingenious contrivance is adopted to facilitate the introduction of the player's left arm into the arm of the figure. To permit this, the arm of the figure requires to be drawn backwards; and for the purpose of concealing, and at the same time explaining this strained attitude, a pipe is ingeniously placed in the automaton's band. For this reason the pipe is not removed till all the other arrangements are completed. When every thing has been thus prepared, the pipe is taken from the figure, and the exhibitor winds up as it were the inclosed machinery, for the double purpose of impressing upon the company the belief that the effect is produced by machinery, and of giving a signal to the player to put in motion the head of the automaton.
This ingenious explanation of the chess automaton is, our author states, greatly confirmed by the regular and undeviating mode of disclosing the interior of the chest; and he also shows that the facts which have been observed respecting the winding up of the machine, "afford positive proof that the axis turned by the key is quite free and unconnected either with a spring or weight, or any system of machinery."
The following letters of reference are employed in all the figures:
A. Front door of the small cupboard
B. Back door of ditto.
C C. Front doors of large cupboard
D. Back door of ditto.
E. Door of ditto.
F. Door of the thigh.
G G. The drawer.
H. Machinery in front 'of the small cupboard.
I. Screen behind the machinery.
K. Opening caused by the removal of part of the floor of the small cupboard.
L. A box which serves to conceal an opening in the floor of the large cupboard, made to facilitate the first position; and which also series as s seat for the third position.
M. A similar box to receive the toes of the player in the first position.
N. The inner chest filling up part of the trunk.
O. The space behind the drawer.
P Q. The false back turning on a joint at Q.
R. Part of the partition formed of cloth stretched tight, which is carried up by the false back to form the opening between the chambers.
S. The opening between the chambers.
T. The opening connecting the trunk and chest, which is partly concealed by the false back.
U. Panel which is slipt aside to admit the player.