Modern Magic: A Practical Treatise on the Art of Conjuring

We will assume that the performer has, in the course of one or other of the tricks already described, secretly obtained possession of a borrowed ring, which the audience believe still to remain in some place or apparatus in which they have seen it deposited. The operator, retiring for an instant, returns with a plate of eggs in one hand, and the dummy egg-cup in the other. The special egg-cup, with the ring already in the mortice, is meanwhile placed either under his waistband, or in one or other of his pochettes, so as to be instantly get-at-able when required. Placing the eggs on the table, he hands round the egg-cup for inspection, that all may observe that it is wholly without preparation, and in turning to place the egg-cup on the table, he substitutes for it the one which contains the ring, but which the audience naturally believe to be that which they have just examined.