when the back door of the cupboard No.  I, is opened.  A bright light then pervades the cupboard, and the body of the man would be discovered if it were there.  But it is not.  The putting the key in the lock of the back door was a signal on hearing which the person concealed brought his body forward to an angle as acute as possible—­throwing it altogether, or nearly so, into the main compartment.  This, however, is a painful position, and cannot be long maintained.  Accordingly we find that Maelzel closes the back door. This being done, there is no reason why the body of the man may not resume its former situation—­for the cupboard is again so dark as to defy scrutiny.  The drawer is now opened, and the legs of the person within drop down behind it in the space it formerly occupied. {*4} There is, consequently, now no longer any part of the man in the main compartment—­his body being behind the machinery in cupboard No. 1, and his legs in the space occupied by the drawer.  The exhibiter, therefore, finds himself at liberty to display the main compartment.  This he does—­opening both its back and front doors—­and no person Is discovered.  The spectators are now satisfied that the whole of the box is exposed to view—­and exposed too, all portions of it at one and the same time.  But of course this is not the case.  They neither see the space behind the drawer, nor the interior of cupboard No. 1 —­the front door of which latter the exhibiter virtually shuts in shutting its back door.  Maelzel, having now rolled the machine around, lifted up the drapery of the Turk, opened the doors in his back and thigh, and shown his trunk to be full of machinery, brings the whole back into its original position, and closes the doors.  The man within is now at liberty to move about.  He gets up into the body of the Turk just so high as to bring his eyes above the level of the chess-board.  It is very probable that he seats himself upon the little square block or protuberance which is seen in a corner of the main compartment when the doors are open.  In this position he sees the chess-board through the bosom of the Turk which is of gauze.  Bringing his right arm across his breast he actuates the little machinery necessary to guide the left arm and the fingers of the figure.  This machinery is situated just beneath the left shoulder of the Turk, and is consequently easily reached by the right hand of the man concealed, if we suppose his right arm brought across the breast.  The motions of the head and eyes, and of the right arm of the figure, as well as the sound echec are produced by other mechanism in the interior, and actuated at will by the man within.  The whole of this mechanism—­that is to say all the mechanism essential to the machine—­is most probably contained within the little cupboard (of about six inches in breadth) partitioned off at the right (the spectators’ right) of the main compartment.