[CHAPTER II.]
The Double Slate.
We now come to a slate called by the mediums “The double slate.” It is, to all appearances, two ordinary slates hinged together at one side and locked with a padlock, the shackle of which passes through a hole in the sides of the frame of each slate. This slate also contains the false flap or slate, but the slate or flap is held firmly in each frame as follows: The inside edges of both ends of each frame of the slates are beveled inward a trifle. One of these ends of each slate frame is also made to slide or pull out about one-quarter of an inch. These are prevented from sliding until wanted by the medium by a catch in the framework, which is connected with a screw in one of the hinges. This screw stands a little higher than the rest, so as to be easily found. The hinges are on the outside of the frame instead of inside. By pressing this screw it undoes the catch, which allows the ends to be moved a trifle. The false flap is just large enough to fill in the space under the bevels of the frame, and if, in the top frame, the catch is released and the end moved, the flap will drop into the bottom slate, where it is held tight and firm by releasing the catch in that frame, moving the end until the flap settles into its place and then sending the end back into its original place again. The writing is placed beforehand on one side of the flap and on one slate, both the written sides face to face, and after the flap has changed slates it presents two slates with written sides.
There is still another double slate used with hinges and padlock. (Fig. 12.)
Fig. 12.—The Sliding Trick Slates.
One of the ends of the wooden frame of one slate is fastened securely to its slate, which is made to slide out completely from the groove in the frame. This allows the insides of both slates to be written upon. After that is done the slate is slid back into its frame. Care should be taken, in sliding the piece back, not to reverse it so as to bring the writing side out. The best way is not to pull the slate completely out, and write upon the inside of the stationary slate, and then reverse the slates, which will bring the inside of the movable slate into view. Write on that and then close the slate.
I have seen a medium use the double or folding slate and get rid of the false flap in this way: He used a pair of small slates. These he opened out with the flat side towards the audience, and while in his hand, cleaned those two sides away from the table. He now showed the reverse sides and cleaned them likewise. He now closed the slates, but toward him, instead of away from him, holding them close to his body, and as he does so, the false flap, by this movement, slips easily and unperceived beneath his coat or vest.