Modern Magic: A Practical Treatise on the Art of Conjuring

Some performers, instead of placing the apparatus in the pocket, as above described, hold it in the right hand (the wand being held in the same hand) and cause it to strike by the pressure of the fingers. This is in one sense less effective, inasmuch as you cannot show the hands empty, but it is a very much more easy and certain method, so far as the striking is concerned. The striking apparatus is generally made to give from fifty to sixty strokes. The performer must be careful not to prolong the trick until the whole are expended, or the unexpected silence of the watch may place him in an embarrassing position. It is hardly necessary to remark that the drawn cards are forced. Where the watch is made to disclose the numbers thrown by a pair of dice, the dice are either loaded, and thus bound to indicate certain given numbers, or a box is used in which a pair of previously-arranged dice take the place, to the eyes of the audience, of the pair just thrown.