An Attempt to Analyse the Automaton Chess Player of Mr. De Kempelen / To Which is Added, a Copious Collection of the Knight's Moves over the Chess Board

by Robert Willis

The general plan and dimensions of the chest will be understood by inspecting the plates, but some particulars, relative to the interior, will require further explanation.

The drawer (gg, plate 5,) when closed, does not reach to the back of the chest; it leaves a space (o) behind it, about 1 foot 2 inches broad, 8 inches high, and 3 feet 11 inches long. This space is never exposed to view.

The small cupboard is divided into two parts by the door or screen ([i, fig. 6],) which is moveable on a hinge, and is so contrived that when b is closed, this screen may be closed also. The machinery (h) occupies the whole of the front division as far as i; the hinder division is nearly empty, and communicates with the space behind the drawer, the floor of this division being removed.

The back of the great cupboard is double, and the part (p q,) to which the quadrants, &c. 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 is composed of cloth stretched tight. [Fig. 10] shews the false back closed. [Fig. 11] shews the same raised, forming the opening (s) between the chambers.

When the trunk of the figure is exposed by lifting up the dress, it will be seen that a great part of it is occupied by an inner trunk (n), which passes off towards the back in the form of an arch, ([fig. 2]), and conceals a portion of the interior from the view of the spectators. This inner trunk opens to the chest by an aperture ([t, fig. 9]), about 1 foot 3 inches high, by 1 foot broad.

When the false back is raised, the two chambers, the trunk, and the space behind the drawer, are all connected together.

The player may be introduced into the chest through the sliding panel ([u, fig. 6]), at the end. He will then elevate the false back of the large cupboard, and assume the position represented by the dotted lines in figs. 3 and 4. Every thing being thus prepared, “the charm’s wound up,” and the exhibiter may begin his operations by opening the door (a). From the crowded and very ingenious disposition of the machinery in this cupboard, the eye is unable to penetrate far beyond the opening, and the spectator is led to conclude that the whole space is occupied with a similar apparatus. This illusion is strengthened and confirmed by observing the glimmering light which plays among the intricacies of the machinery, and occasionally meets the eye, when the lighted candle is held at the door (b). A fact, too, is ascertained, which is equally satisfactory, though indeed for opposite reasons, to the spectator and the exhibiter, viz. that no opake body of any magnitude is interposed between the light and the spectator’s eye. The door (b) must now be locked, and the screen (i) closed, which being done at the moment the light is withdrawn, will wholly escape observation.

It has already been mentioned, that the door (b), from its construction, closes by its own weight; but as the player’s head will presently be very near it, the secret would be endangered, if, in turning round the chest, this door were, by any accident, to fly open; it becomes necessary, therefore, “to make assurance double sure,” and turn the key. If the circumstance should be observed, it will probably be considered as accidental, the keys being immediately wanted for the other locks.

The opening (b) being once secured, and the screen (i) closed, the success of the experiment may be deemed complete. The secret is no longer exposed to hazard; and the exhibiter is at liberty to shape his conduct in any way, he may think, most likely to secure the confidence of the spectators, and lead them insensibly from the main object of pursuit. The door (a) may be safely left open; and this will tend to confirm the opinion, which the spectators probably formed on viewing the candle through this cupboard, that no person was concealed within it: it will further assure them that nothing can pass in the interior without their knowledge, so long as this door continues open.

The drawer stands next in the order of succession: it is opened, apparently, for the purpose of taking out the chess men, cushion, &c. but really to allow time for the player to change his position, ([see fig. 5].) and to replace the false back and the partition, preparatory to the opening of the great cupboard.