Fig. 1.—Ordinary Slate with Flap.
Another way of utilizing the false flap is as follows: The writing is not placed beforehand on the slate, but on the flap, which, as before, is covered with the same material as the table top. This is lying on the table writing downward. The slate is handed around for inspection, and, on being returned to the performer, he stands at the table and cleans the slate on one side, then turns it over and cleans the other. As he does so he lifts the flap into the slate. The flap is held in firmly by an edging of thin pure sheet rubber cemented on the flap between the slate and the cloth covering of the slate. This grips the wooden sides of the frame hard enough to prevent the false piece from tumbling out accidentally.
We now come to another style, wherein a slate is cleaned on both sides, and, while held in the hand facing the audience, becomes suddenly covered with writing, and the slate is immediately given for inspection. The writing is on the slate previous to the cleaning, and is hidden from view by a flap of slate colored silk, held firmly in place by a pellet of wax in each of the corners of the silk. Attached to this silk flap or covering (at the end that is nearest to the performer’s sleeve) is a stout cord or string, which is also made fast to a strap around the wrist of the hand opposite to that holding the slate. If the arms are now extended their full length, the piece of silk covering will leave the slate and pass rapidly up the sleeve out of the way, and thus leave the writing exposed to view. (Fig. 2.) The slate is found to be still a little damp from the cleaning with the sponge and water it had been given previously. This is easily accounted for. The water from the sponge penetrates just enough through the cloth to dampen the slate.
Fig. 2.—Removing the Silk from the Face of the Slate.
There is still another slate on which we can make the writing appear suddenly. It is composed of a wooden frame, such as all wooden-edged slates have, but the slate itself is a sham. It is a piece of cloth painted with a kind of paint known as liquid, or silicate slating, which, when dry and hard, is similar to the real article. This cloth is twice the length of the slate and just the exact width. The two ends of the cloth are united with cement, so as to make an endless piece or loop. There is a small rod or roller in both the top and bottom pieces of the frame, the ends being made hollow to receive them. Over these rollers runs the cloth, stretched firmly and tightly. Just where the cloth is joined or cemented is a little black button, or stud of hard rubber or leather. This allows the cloth to be pushed up and down, bringing the back to the front; and by doing so quickly, the writing which is written on the cloth at the rear of the frame is made to come to the front in plain view. (Fig. 3.)
Fig. 3.—The Endless Band
Silicate Trick Slate.
Still another idea in a single slate is as follows: An ordinary looking slate is given out for examination, and, on its being returned to the medium, he takes his handkerchief and cleans or brushes both sides of the slate with it; and, upon again showing that side of the slate first cleaned, it is found covered with writing apparently done with chalk. The following is the simple explanation of it: Take a small camel’s hair brush and dip it in urine or onion juice, and with it write or trace on the slate whatever you desire, and when it becomes dry, or nearly so, the slate can be given for examination without fear of detection. The handkerchief the performer uses to clean the slate with is lightly sprinkled with powdered chalk. He makes believe to clean the one side devoid of preparation, but the side containing the invisible writing is gently rubbed with the handkerchief, not too hard just enough to let the powdered chalk fall on the urine or onion juice, where it leaves a mark not unlike a chalk mark.