“The rest is a very simple matter. The person who is to represent the Sphinx is beforehand placed, duly attired, underneath the table. There is a trap in the table through which he can pass his head at the proper moment. This trap is a round piece of wood, covered to match the surface of the table, and working on a hinge on the side nearest to the audience. It has no spring, but is kept closed by means of a button on the opposite side, and when released hangs down perpendicularly. It must be large enough to allow the passage of the somewhat elaborate headpiece of the Sphinx, and would therefore leave an open space visible round the neck. This difficulty is met by the expedient of having a wooden collar, the upper surface of which is a facsimile in size and pattern of the trap. This collar is fastened round the neck of the representative of the Sphinx. When he lifts his head up through the trap, the collar exactly fills the opening, and thus shows no break in the surface of the table. The box is bottomless, and when brought forward by the performer is empty. A little caution has to be observed in placing it upon the table, for, if the performer were to approach the table _from the side_, his legs would be reflected in the glass, and would thereby betray the secret. He must therefore make his appearance from some quarter _outside_ of the curtained recess, and advance to a position well in front of, and at some little distance from the table, when, by moving in a straight line from the audience towards the middle leg _a_, he prevents this inconvenient reflection. The placing the box upon the table, and the unlocking it, allow time for the representative of the Sphinx to get his head into position within it. This done, the box is opened, and the rest depends on the dramatic talent of the performer and his assistant. The performance being concluded, the box is again locked, and the head withdrawn, a handful of ashes being introduced on the trap in its stead. “The angle at which the two mirrors should be set cannot be determined absolutely, but will vary according to the distance and position of the surrounding drapery.”