“Turn over the slate,” said the juggler.
I complied with his request and found a long message to me, covering the entire side of the slate. It was signed “Cagliostro.”
“What do you think of Dr. Slade’s slate tests?” inquired C—.
“Splendid!” I replied, “but how are they done?”
His explanations made the seeming marvel perfectly plain. While the slate is being examined in the first test, the medium slips on a thimble with a piece of slate pencil attached or else has a tiny bit of pencil under his finger nail. In the act of holding the slate under the table, he writes the short message backwards on its under side. It becomes necessary, however, to turn the slate over before exhibiting it to the sitter, so that the writing may appear to have been written on its upper surface—the side that has been pressed to the table. To accomplish this the medium pretends to go into a sort of neurotic convulsion, during which state the slate is jerked away from the sitter, presumably by spirit power, and is turned over in the required position. It is not immediately brought up for examination but is held for a few seconds underneath the table top, and then produced with a certain amount of deliberation.
The special difficulty of this trick consists in the medium’s ability to write in reverse upon the under surface of the slate. If he wrote from left to right, in the ordinary method, it would, of course, reverse the message when the slate is examined, and give a decided clue to the mystery. This inscribing in reverse, or mirror writing, as it is often called, is exceedingly difficult to do, but nothing is impossible to a Slade.
But how is the writing done on the slate in the second test? asks the curious reader. Nothing easier! The servant who raps at the door brings with him, concealed under his coat, a second slate, upon which the long message is written. Over the writing is a pad cut from a book-slate, exactly fitting the frame of the prepared slate. It is impossible to detect the fraud when the light in the room is a trifle obscure. The medium makes an exchange of slates, returns to the table, washes both sides of the trick slate, and carelessly exhibits it to the sitter, the writing being protected of course by the pad. Before placing the slate under the chafing-dish cover, he lets the pad drop into his lap. Now comes a crucial point in the imposture: the writing heard beneath the slate, supposed to be the work of a disembodied spirit. The medium under cover of his handkerchief removes from his pocket an instrument known as a “pencil-clamp.” This clamp consists of a small block of wood with two sharp steel points protruding from the upper edge and a piece of slate pencil fixed in the lower. The medium presses the steel points into the under surface of the table with sufficient force to attach the block securely to the table, and then rubs a pencil, previously attached to his right knee by silk sutures, against the side of the pencil fastened to the apparatus. The noise produced thereby exactly simulates that of writing upon a slate. In my case the illusion was perfect. During the examination of the message, the medium has ample opportunity to secrete the false pad and the clamp in his pocket. Instead of having a servant bring the slate to him and making the exchange described above, he may have the trick slate concealed about him before the séance begins, with the message written on it, and adroitly make the substitution while the sitter is engaged in lowering the light. Dr. Slade almost invariably adopted the first-mentioned exchange, because it enabled his confederate to write a lucid message to the sitter.
An examination of the sitter’s overcoat in the hall frequently yielded valuable information in the way of names and initials extracted from letters, sealed or unsealed. Sealed letters? Yes; it is an easy matter to steam a gummed envelope, open it, and seal it again. Another method is to wet the sealed envelope with a sponge dipped in alcohol. The writing will show up tolerably well if written upon a card. In a very short time the envelope will dry and exhibit no evidence of having been tampered with.
And now as to the rest of the phenomena witnessed that evening in C—’s room. The raps on the table top were the result of an ingenious, hidden mechanism, worked by electricity; the mysterious hand that operated under the table was the juggler’s right foot. He wore slippers and had the toe part of one stocking cut away. By dropping the slipper from his foot he was enabled to pull the edge of my coat, lift and shove a chair away, and perform sundry other ghostly evolutions, thanks to a well trained big toe. Dr. Slade who was long and lithe of limb, worked this dodge to perfection, prior to the paralytic attack which partly disabled his lower limbs.
The stringed instrument which played in the cabinet was arranged as follows: Inside of the guitar was a small musical box, so arranged that the steel vibrating tongues of the box came in contact with a small piece of writing paper. When the box was set to going by means of an electric current, it closely imitated the twanging of a guitar, just as a sheet of music when laid on the strings of a piano simulates a banjo. This spirit guitar is a very useful instrument in the hands of a medium. It may be made to play when it is attached to a telescopic rod, and waved in phosphorescent curves over the heads of a circle of believers in the dark séance.